I think the actual problem is that they can't make any country superior to another because then there would be even more whining, stuff like "I can't beat half stack of prussians with 1 full stack that is OVERPOWERED OMFG!!111LOLXD"
I don't know if it was my lack of skill or what but one of my earliest games as Prussia I didn't have much trouble with any battles but my economy was a mess and as I tried to revive it my actions were much like in South Park episode Margaritaville... Continental powers like Russia, Austria, Prussia and Poland-Lithuania are econimically screwed from day 1 (not to mention they all have to fight each other to further screw them up) leaving them easy pickings for trade powers like France and Great Britain.
And what annoys me the most is that minor nations either trade each other technologies or get major boost to their research. Unless I concentrate on enlightment tech or have lots of schools from start all German minors get Modern Universities way earlier than me.