I purchased the Warhammer Quest iOS game back in 2013 or 14, and played it a bunch then, and now I've started playing again. While it has some design flaws (some of the game mechanics cause me actual physical pain), there's also a lot of merit to this fairly simplistic dungeoncrawling game. I might write a review of it later, elsewhere; this post contains some of my thoughts on good strategy in the game.
Character advancement seems to be randomized. Not only do you get random stat boosts (my level 4 Grey Mage still had only a Power Store of 6, WTF!!!), but characters also appear to randomly gain Spells and Abilities as they level up. For instance, in my recent game the Grey Mage seemed to learn different Spells from when I last played (a cople of years ago), and likewise the Abilities gained by non-caster characters. For instance my Waywatcher in this game gained a once-per-dungeon self-buff to increase effective Ballistic Skill, which I'm not at all sure I've seen before.
What can you do about this? Almost nothing. The only thing I guess you can do is to retire a character if you think it has mis-developped, and then bring a new level 1 character of the same class into the party, and try to ding him up. But that seems difficult to me, since the only ways to gain XP are direct combat: Killing enemies, and healing allies.
And yes, that's right. The one character who strikes the final blow gets the XP. It doesn't matter if your Grey Mage burns his Power Store on casting two AoE Spells to drastically reduce the HP of a cluster of Zombies, and then your Waywatcher comes in with her bow and kills the Zombies easily. Waywatcher gets the XP. Healing does seem to give an at least decent amount of XP, but the "Winds" effect is (as far as I've read, and my experience seems to match this) is an 1d6 roll plus the level of the Grey Mage (and you get a flat zero on a roll of 1), and the healing Spell you start with (as far as I can remember that's not randomized) costs 5 power to cast, so you can use it 1/3 of the time.
However, you want to finish each dungeon fairly quickly, I think, because each turn there's a random chance of wandering monsters trying to gank your asses, whether you're already in combat or not. Some text on the web suggest that this happens every time you roll the 1 on the Winds roll, but there's a lot of misinformation about the iOS game out there; I have personally seen 0 power Wind outcomes that didn't result in wandering monsters.
Role specialization might be good. It seems to me as if the Marauder is the first of your two fighter types to get a 2nd melee ttack, and mine also gained an Ability that sometimes gave him twice as many melee attacks as normal (Battle Blades I think). Thus suggests to me that the Marauder shall be the main damage-dealer, with emphasis on a high-damage melee weapon (preferably a two-hander - fuck shields!), and on items that boosts his Strength, while the Dwarven Ironbreaker shall be the tank, with emphasis on Toughness and other defences (and of course a shield and a one-handed weapon). Also monsters will (at least usually) strike at the character who attacked them last, so in this situation it should be optimal to hit strong monsters first with the Marauder, then with the Ironbreaker, but I have not yet actually tried this.
Optimal Gold expenditure seems important. I like Rings of Regeneration a lot, they help the party members heal up gradually while walking the dungeon. From the first time around I played, 2013-14, I seem to recall lesser Rings of Regeneration costing 800 Gold and giving +1 HP per turn, but these have consistently failed to show up in my current 2016 game; Instead I'm forced to choose between nothing or more powerful Rings giving +2 HP per turn but costing 2000 Gold. That's fine in itself, but the problem is in my current game I first bought 1 of these (which was fine), then quickly thereafter bought 2 more, which was too early.
In particular, I think what went wrong in my current game is I focused overmuch on defence (especially since I don't play on 'ardcore mode, so I can in theory tolerate several of my guys dying) and didn't really do anything at all about damage output, meaning my guys mostly still use crappy weapons, only the IronBreaker wielding a decent 6-8 damage one-hander. I think with the DPS/Tank division, it does make sense to quickly get the Tank a Ring of Regeneration, although preferably starting with a cheaper +1/turn one if possible (that one can always be passed down to the Grey Mage or Waywatcher later, and I distinctly recall having done that when I first played, in 2013 or 14).
Another thing I did, albeit comparatively less expensive, was to purchase a bow for my Marauder. My line of thought was, hey, this can can actually shoot, so why not give him the tool to enable him to use that ability? Problem is, I paid something like 600 Gold for the Common-tier bow, and he gets 1 shot per round. So that alone is around 4600 Gold wasted on 2 Rings and a Bow all purchased too early (the Bow for the Marauder makes a lot more senes later, when he gets better Ballistics Skill and hopefully 2 shots per turn).
In the starting region, the shops aren't too interesting, except the town to the west (there are about 7 towns in the starting region) which sells magic rings (that's where you can purchase the 2kG Rings of Regeneration, although I seem to recall that they also sold the 800 Gold ones a couple of years ago), and another town, or rather city, to the northeast of that one, which has a Masterwork Blacksmith store, so that's where I should have gone more to spend some of thoes 4600 Gold more wisely (he seems to sell only weapons, though, not armour).
The 2 other regions have their own towns and markets, but I don't recall much of them. Some recycle existing markets (like the "Black" Market" and another Masterwork Blacksmith) but some may be more interesting, I sadly don't remember.
Note I'm not saying you shouldn't buy Rings of Regeneration. Eventually you should, because they're very useful. I just think I priortized very wrong in my current game, wrong enough to be worth sharing my mistakes (and wrong enough to abandon that game, with 2 dudes being level 5 and the other 2 being level 4, and start over).
One unanswered question: How do the various healing items differ? Food rations are much cheaper than Bandages, yet I have been well able to have one character use his food on another character. Food rations probably don't work on unconscious targets, but still, it just seems as if Bandages are overly expensive.
Some quick comparison of tier-1 and tier-2 Bandages (green and blue):
Green, cost 30 gold, heals 1-3 HP, average 2, cost 15 Gold/HP
Blue, cost 180 gold, heals 4-6 HP, average 5, cost 36 Gold/HP
Not sure about Potions of Healing, I tend to not use those.
I guess it comes down to slot availability, and also market availability, with green Bandages seeming rarer than green food (which costs only 10 Gold and still heals 1-3 HP, so costs only 5 Gold per HP) and blue Bandages being rarer still. I think if possible one ought to purchase aggressively when able, stock up on stuff when available? I think saving just 6-8 group inventory tiles free may be enough, or 10 to be sure, then the rest can be filled with food and Bandages.
There are also blue rations, but I don't recall their stats.
I don't like Firebombs much. Cost 100 Gold, and do the same 3x3 AoE as the Grey Mage's AoE Spell which means it's difficult to use well, either you hit your own dudes or else you only cream 2-3 or a maxmum of 4 monsters. getting 3 or even just 2 monsters for free with a Spell is OK, since power regenerates, but wasting 100 Gold for that? I think that's a very bad idea.
Another mistake I made (they seem to come by the truckload, in this game) is after I found a neat blue 2500 Gold one-handed weapon for my Ironbreaker, replacing his older green two-hander with that, I wanted a shield for him, but I accidentally purchased on that was Marauder only, so that was another 1000 or 1200 Gold wasted even taking into account 25% sell-back recoup (what's the tally now? 5600 Gold wasted so far, although granted 4000 of those weren't totally wasted).
I've always thought, and various others on the web agree with me, that it is worthwhile to get the Grey Mage a better melee weapon. I think he starts with a green sword. Replacing that with a Dagger gives +1 attack/turn, but again damage output, it might well be better to go for one of those sword types that he can actually use. Simply to help him earn more XP.
Oh, and one important thing: Try to keep money in store for training your dudes after they ding up. As I recall it's 200, 500, 1000 then 2000 Gold. They do continue to earn XP after getting enough to level up, I am absolutely sure of that, based on what I've seen in-game, but it still feels stupid and annoying crawling around in a dungeon with a dude who is ready to be trained, and who might gain some valuable new stat bonus or Ability or Spell from such training.
So, in short, this game is very much about managing your Gold.