EDIT: I'm talking about 3v3+ modes.
I know that you are not biased so that only leaves, and I'm sorry, but severely misguided. There is nothing wrong with only 1 ranger commander? I on the other hand like the rangers in USF. Gives the raw power aspect through a commander that does not need a huge muni dump overall like all other USF units do. If you make every unit be some sort of USF gimmick, then USF will be a boring faction. Look, all my units are weak compared to axis counterparts but they have abilities that go BRRRRR. And sometimes that BRRRR is awesome (scott smoke, M20 mines, captain On Me..), other times it's severely situational and prone to error (pershing skill shot, echelon suppressed fire, AT gun hvap).
[[ before you go commenting how AT gun HVAP is great. Overall it is, but that first shot is important and unless you know that there is a tank coming, you won't preemptively pop the hvap ]]
Your vision is to make every USF unit a muni dump? What are the reasons that USF can NOT have DOCTRINAL power units?
Arguments I will give in favor of USF having doctrinal units that are as you say "Power units":
More variety in the gameplay:
Power units don't usually have a lot of flexibility so you reinforce that flexibility by stock supporting units.
Example: Pershing and CA (my problem is that CA does not justify Pershing's weaknesses and costs a lot until the very late game where you have a lot of munis, but that is another thread....)
Axis winrate in teamgames and the general easier grasp of their style of play proves this. In 1v1s, USF is great because of all their stock versatile options (A bit put off by the fact that mech is #1 pick BY FAR), and in teamgames their winrate falls flat mainly because you do not need a unit with 20 abilities. Teamgames mostly relies on how well you control your units on a tighter space (eg. a VP lane based on where you spawn). There are a lot more sources of danger in 3v3+ so on a tighter space you need units that you can rely on and not having to TAB between them like a madman to use all the abilities so that they can stand their ground.
Power units relieve that problem. You know that you can leave your KT parked there and pay attention to something else, because even if it does get assaulted, it has enough hp/armour to stand the ground and plenty of time to retreat.
My argument then is that doctrinal power units would give USF more teamgame staying power. And if you make more commanders, then you won't see every f****** game a Calliope commander. Only time when you don't need to go for the Calliope if it's playing against braindeads (non braindead people know that if no calliope, you can overwhelm USF with numbers alone, especially if no rifle mines).
Allowing more commanders:
Sort of a continuation of the previous argument. You can design commanders around power units much more easily than around "pure versatility". I'd even argue that the "USF is versatile" has gone down the drain long ago through updates and patches. The only shtick they have now is the repair crews and strong mainline upgradable infantry (read: BARs on rifles, zooks on echelons if you value winning).
The game went from pure asymmetrical chaosgame to a predictable symmetrical game through cookie-cutting and "more in line with" arguments. And you can't argue that. It's self evident through CTRL-F "in line" search through the update notes on Updates forum. I just went through the updates just finding the "in line" words. 41 total on pages 4,5,6. That's only counting "in line". I'd shudder to think to go through the notes to see all the cookie cutting changes that have occurred to water down units and "rework" them.