Basically, it's this.
If we tune Jackson to miss vs target-size 2 P4's, it's going to also miss vs target size 26 KTs. And, oh boy, it's also going to miss a lot vs target-size 13 Blitzking KTs.
You don't need target tables to settle this. You just need target sizes that make sense.
I'm guessing you mean 20-something when you say 2 right?
Actually nope. Usf just doesnt have access to everything at once like okw has. You either get access to mg or to an at gun. xD If you go lt you dont have access to an at gun but you are a little bit better vs AI. Cpt tier is more AT. It would be fine if LT was actually heavy AI and gave you something like luchs that is actually worth rushing for but what you do get is a miserable m20 that is hardly usefu;, a poor replica of an mg with very bad stats and AA ht that can only attack when turned backwards (which is a micro hell). Only thing actually good from LT tier is the LT because he has a bar and thompson gun which makes him great vs infantry. Besides him the units are not even mediocre. They are just bad at their main purpose. But its just fun to do something else for a change instead of defualting to cpt because you know lt tier is basically useless.
Now OKW on the other hand has a lot of tactical differences and advantages of each tier. Med truck gives you FRP, healing (on top of volks self healing and sturmpios med packages), autofire isg requiring no micro at all with great range, excellent AA ht with instapin and high dps and a cheating see through fog of war unit. Mech truck gives you the best and the fastest arty in game, best light AT vehicle in the game, best light AI vehicle in the game. Not to mention that either of them unlocks both fausts, nades and stg44 for your main infantry. Now thats what I call a great upgrade packet, usf has to pay 300 mp and 40 fuel to get the same. And each of these tiers gives you access to fantastic units and different playstyles. I mean what else could you even dream of in this game? Am I right? And all of this while also having always access to an at gun? WOW its so much fun! So yeah usf in return would humbly like to have access to both at gun and a tank without being forced to go a specific tier all the time, nothing special, just normal.
The point about not having access to things as usf is very valid, but I feel like you sell some things a bit too short. The .50 is actually really good, as it has great dps and a very fast setup/teardown, and can penetrate 222s and pumas. It does seem to be very inconsistent at suppressing though, sometimes doing it in less than one burst, and sometimes taking at least 2 full ones, which sucks because they're very short with long delays in between. The AAHT only shooting backwards isn't a huge deal, not enough to really mess with it beyond the shitty pathing that often means the death of a lot of light vehicles, and it doesn't have to setup or anything like the okw halftrack (which has its own merits). I find it a much better choice than the Stuart now, and people often forget it can pen luchs back, which is funny (it'll still lose badly in a 1v1 ofc, because Germans or something). The m20 is just severely overpriced.
Armour values aren't so bad (at least nowhere near as terrible as popcap and target size). What's bad is that penetration values across the board are very flat. Your medium tank has roughly the same chance to penetrate while sniping the enemy heavy from afar, just like going point blank (where it's kill-or-be killed territory).
At the same time, vehicles also lack side armour, which means that firing from the side might lead to, sometimes, your shots hitting front, or sometimes hitting the juicy rear armour. Since rear armour for heavies has been nerfed to be almost always penetrated by mediums at any range, you get the frustrating frontal rear-armour snipes that degrade heavies.
Also, designing a turreted tank that has a very high penetration gun might lead to pantheritis, where you get no reward for flanking the enemy (except for risking your own very expensive vehicle).
But yeah; penetration is the way to go if you want to draw a line between efficiency vs mediums and efficiency vs heavies.
I seem to notice that shermans have a decent chance of sometimes maybe penning a (nonvetted) panther frontally at really close range, like while I'm trying to flank, which isn't something I'd bet even one rifleman model on at long range, let alone a sherman. Same thing seems to apply to small cannons (base 20mms, flakhq, ostwind, etc) to sherman front armor. Other than that, I've never really noticed range making a difference, which kinda sucks.