The new tools introduced were not well designed. EFA was designed with its counterparts in mind. WFA didn't give a shit at all and THAT is the cause of EFA reworks,not poor design.
The same could be said about the EFA and WFA as well.
The old EFA tools were not designed to fight anything apart from each other, and the WFA were designed with their counterpart in mind. So Ost vs Soviets would be balanced, and OKW vs USF would be balanced as well, because they were again like I already said designed with each other in mind, but not to cross over.
We're seeing the fallout of that years later.
Want an example? The original CoH's Armies, upon the addition of the Panzer Elite and Brits with Opposing Fronts it added new flavor to the game but didn't break it, and the original Armies were all around at least for the most part more popular, chosen and arguably superior.
They introduced radical new designs but Relic didn't have to do 5 reworks for each Army to get them in line.
Of course there's also the Brits here who I am guessing were designed to fight the OKW and not Ost and that's perhaps why they fair so badly against the Ostheer which is yet another example of bad core Army design in general.