Hmm in response to the original poster:
It is actually more fair than you think, at least with division modifiers. While with attack skills you can choose to increase only one division bonus (charge for cavalry), you can only use it for one troop type. You still need all 4 of them if you want to lead other troops than cavalry. The only reason this seems lopsided is because most people choose to specialize. But if you don't, you're gonna need more than just charge.
While defense skills do indeed number 4, you only need 1 if you expect to be attacked by a specific troop type. If you're defending on plains, you can expect to be hit by cavalry and cavalry defense is useful. It also works for ALL YOUR troop types. Unlike the offensive ones, which are troop specific. So you can defend with a combination of cavalry and spears and you will still only need one defense skill if you know you'll be hit by cavalry. You cannot do this on attack.
So the 4 to 1 thing works both ways for offense and defense with division modifiers.
It is only really off/unfair for personal skills. Heroism works for all offense and the personal defense skills work only for one type each. Heroism is pretty much overpowered. Not that it matters because most people will take it before anything else so noone has an unfair advantage.
As for heroism being so much stronger than divisional offense. This is true in most cases, but many veterans have 5-10k troops per town, at which point they are comparable. The thing that really makes heroism strong is that they stack for different commanders. You can have 5 heroism 10 commanders in an army, but you can only have one charge bonus (for cavalry troops)
In the end it matters little. Everyone with commander levels 30-40 will both have heroism and a divisional modifier maxed. It is the rest of the skills that will vary from player to player.
Edited by Innoble - 14 Jun 2012 at 21:55