I havent stopped playing since I got it... I have been playing in expert and i get massively owned no matter what i do.. but despite there only being one 'race' i feel like the game is different every time. So far anyways
Be patient it's only a matter of practice. It's normal difficulty when enemy's soldiers don't get punished with reduced HP because you are such a sissy that can't endure some challenge and learning curve. And there is no such thing as "playing race" in terms of HoMM - almost any creature in this game is playable as army unit. Your stronghold unit roaster is customizable for you to be able to adapt to any situation and path to have reliable source of troops. Only "Army of Light" path is pretty much set. Your armies and heroes are very adaptive.
OK. I'll provide some tips for expert difficulty.
Starting heroes.
Warrior can live solo at levels 7-10. Right from the start he'll need help of troops, later he can give them to second hero. Warrior has not too much options and combat methods so he is fastest to master, to learn how to play him right.
Scout can cripple advancing enemies, has very important skill Pathfinding which greatly improves your units freedom of movement and this is very important. Scout cannot fight without army. He specialize on delivering damage where it needed most to keep his army safe. He has moderate army which main purpose is to shield scout - this limits the variety of combat methods you'll need to master to play him right.
2 other heroes need more skill and knowledge to master so I will not provide tips for them.
Wounded or winded units cannot act with full effectiveness. Most of the time you will combat overwhelming forces so you'll need every chance to gain advantage. You need to know how stamina works.
Every time unit attacks or counterattacks he spends 1 stamina point. When he moves through rough terrain without knowledge of this terrain he spends additional stamina points. If he moves and attacks in same round he spends additional stamina point. Thus stamina can be depleted very fast if you're not careful. AI is very aggressive and it can be used to force him to spend stamina fast. Units without stamina will have their armor values halved - you need to avoid this by resting even under strikes because it'll be much worse if you'll pass out.
AI likes to do maximum damage and kill units like healers, archers and mages with focused ranged fire if he has such opportunity. If he can step forward and shoot your healer he'll do it instead of shooting your swordsman but if he can't reach shooting distance this turn but can shoot swordsman than he'll shoot swordsman without advancing. Most of the time but not always it's not that simple but most of the time it'll work.
Hexes are there not just for lulz. You can position your unit in such manner that only one enemy can hit it in melee because his buddies will block other directions in armored wall. And Swordsman have ability to Parry one attack in round increasing his Armor for this attack. Wounded and winded enemies deal much less damage so sometimes it's better to keep them alive and rest and heal under their weakened strikes than kill that pesky Goblin with counterattack and allow fresh Orc to take his place and crush your stupid head with morningstar strike.
Very reliable and not very sophisticated start is Warrior + 2 Swordsmen + 1 Healer. Such combination will allow you to fully shield your healer from melee in lower left corner of battlefield:
S1 W
H S2
Your Swordsman 1 (S1) will face only 1 hex, second (S2) will face 2, and you Warrior (W) will face 3, Healer (H) is fully protected from melee and can heal. But H can be targeted by shooters so you can't just hold this position while there are shooters with ammo so you need to deal with them. You can soak their ammo with armored units, burn their ammo (T1 spell), shield your healer with T1 spell, burn shooters stamina with T0 spell etc.
Described position is the last stand position, usually in the beginning you will advance with armored units to soak missiles and to prevent shooters to target your Healer. After initial clash you will slowly retreat to force opponent to move and strike to make him to spend stamina faster and become weaker. Then you'll shield your Healer with spell and your bodies to let him survive remaining ammo and heal your wounded soldiers.
Something like that, I don't want to steal your fun and reveal secrets and tricks - only basics.
