You are entitled to your opinion but I have to point out some thing you got wrong, at least imo.
USF have not suffered from repair speed nerfs. They still have some of the best repair speed with crews.
The heavy supper repairing speed was simply broken, they might have overnerfed it but it used to be broken.
Part of the reason it was done was because OKW vehicles where being repaired too fast.
When they brought Penals to "WFA level" they where competently and utterly broken because they combined WFA level weapons, Flamers, ourah and Soviet level veterancy bonuses combining the best of all worlds.
Increasing the power level means that game becomes more about reaction time and less about strategic thinking, so it lose depth.
But you are still missing my point. One has to use a benchmark and balance units around that benchmark. That benchmark is grenadiers so they can not be UP, other thing are simply OP.
Say what you may, my arguments are based upon facts proven as time has gone on, however your "benchmark" is now entirely your own opinion and one could even say that it's biased since I haven't noticed your explanation on it, why not have the Conscripts as a benchmark, why the Grenadiers? Why can't we have the WFA Armies' 5 man squads as a benchmark instead since they seem to be a bit easier to balance?
The Ostheer's 4 man Grenadier squads have low survivability and only lead to balance and design headaches where you're giving them 25% of their firepower in the form of the MG42 upgrade to mimic the 5 rifles shooting at them on the other side and giving them slightly more HP for each model to again mimic the survivability of the other guy's mainline unit, why? Why go through the cheesy and gimmicky route and not instead make them a 5 man squad and balance them another way.
The conscripts on the other hand represent the other extreme of being a 6 man squad but having low utility, scalability and usefulness without a doctrine (Conscript repairs, PPSh packages, etc.). People replaced them with the Maxim MG squads before, now they're being replaced by the Panels, why not just make them a 5 man squad with non-doctrinal upgrade(s) and be done with it, why the need to constantly have a non-doc replacement for them when they're meant to be your mainline infantry unit and not a support such?
It's these reasons that I deem why the EFA are so unpopular compared to the WFA and how their designs are also very flawed, so having them as "your benchmark" means that you're only going to ruin everyone else and get rid of any pleasable gameplay experience.
In the end the EFA are as gimmicky if not more than the WFA relying on unreliable mainline infantry units, no alternative repair methods non-doctrinally, no forward retreat points non-doctrinally, heavily relying on strong commander choices or risk losing the match 90% of the time in the Soviets' case and having to heavily rely on call in infantry units in the case of the Ostheer, why do you think Osttruppen are so popular, or why Ass grens dominated back when they aren't so shit?
This system of seemingly crippling an Army forcing the player to choose the same commander over and over again to plug a huge gap seems to be very detrimental for everybody.