A game can be balanced for lower skilled players.
Imagine you have two factions:
Faction A) slow, defensive, sturdy, good relation of cost to damage and health points/armor, complete roster
Faction B) fast, aggressive, high damage but low health/armor, many special abilities, roster with holes
Faction B will be very strong in the hands of skilled players which have the micro skills and the understanding to utilize speed and combinations of abilities to full effect. In addition a skilled players can partly compensate the missing pieces in a roster. As a result Faction B will be nerfed constantly although it was underpowered in lower skilled play from the beginning.
In addition Faction B will be better in 1vs1 and worse in 4vs4. Reason: At 1vs1 maps there is a lot more space for moving, flanking, evading and relocating.
Exchange Faction A with Ostheer and Faction B with USF now to get the idea ;-)
For a good balance across all skill levels all factions should have units that fit the style of Faction A and Faction B. CoH2 severely fails at that.
Low level players being unable to play USF has nothing to do with higher mechanical requirements imo. USF just requires a slightly different way of thinking about the game and that makes 90% of coh2's playerbase's heads explode. Any new player approaching the game with a rational mindset can still become top 200 (and probably higher) within 500 hours. That goes to show how terrible the established playerbase really is. Most people are incapable of analysing this game rationally because they have this irresistable desire to blame their own faults on the game or their opponent.