One not-so-great thing about the fourth game is that the hero fights like a regular soldier.

I think it's the opposite; it makes the fourth game unique... that's its charm... and it doesn't just make him a regular soldier, but a super soldier (depending on the build!).

When I played the fourth game (I hardly play it anymore, I've switched to the fifth), I really enjoyed this feature. In the campaigns, starting from the second or third mission, I mostly fought with just heroes (meaning without an army) to speed up the gameplay. However, even then, I started to think that it was almost like cheating – when one guy, even if he's a super-duper hero, takes down dozens of dragons and other high-level monsters... You have to agree, it's not very believable. Now, after playing the fifth game, I think that this possibility is implemented better there (at least more realistically): if you want to swing a sword, go ahead; if you like to cast spells, that's fine too, but even the coolest hero can't kill more than one (or maybe two) dragons at a time. That's more believable. But overall, I like the fourth game; I'm not one of those who criticize it, especially not one of those who do it without having played it much.