It needs to be better than MoM,
So true!
I admit I too love MoM and it's combat system. But it had some major flaws as it was very easy to make an unbeatable army. Heck some units with various immunities could simply walk over whole cities by themselves. There were more then a few rush tactics based off of these units. In fact I recall one of them basically taking advantage of a unit that had "first strike" ability. The problem was the AI often had no way to counter these rushes and thus wouldn't put up much of a challenge.
I do think units need more HP in general though. It's way to easy to get enough attack to one shot quys really early. The first thing I always research in Military is Party so I get units of 4. This means I can field a peasent party with 12 ATK and 20 HP. Next I got for basic weapons so I can get the axe and now I got a unit with 4x6 ATK = 24 Attack and 20 HP and the game hasn't been going for that long. These fairly cheap units are easy to produce in mass and easily own anything I encounter early on. They put my SOV to shame and I only keep the SOV in the group to leech XP.
When a lot of early monsters have 2-8 HP but have 3-6 ATK it only takes 1-2 hits to take out an unarmed unit with 5 HP. And as for as your SOV and heroes they only have 10 HP and can go down in 2-3 hits vs those early monsters unless you bought armor. But even with armor when units start showing up with 9-24 ATK a little into the game that 10 HP means your got be real careful cause getting high defense is EXPENSIVE.
So far I've learned caster heroes ROCK, while all others are just XP leeches unless you get a couple levels increase their HP and spend several hundred gildar on equipment. Basically the price to field a large army for a single unit that's not that great when the army you bought for equal cost would own that units.
And the talk of heroes that use the clearly broken system of unlimited magical item equip to get uber high defenses is kind of a pointless arguement. I garrentee you that for the thousands they spend to make that ONE unit I can build an army of Company units (12 guys) with at least 72 ATK fairly easily because that's the basic attack of ones that simply have an 6 ATK Axe. There are better weapons and their total HP of 60 for basic troops (90 HP Vets, 120 HP Elites) means they could easily stand up to that single uber unit. Plus just add some basic armor and they can have better damage resistance thus greatly increasing survivability. Since they also cost a fraction of the price you can field several of them and easily take on that one unit.