Jesus Christ guys, USF can only build Riflemen while Wehrmacht give you an option to build T0 MG-42 and Grens. Combined Arms is they key in winning engagements.
And does USF really need much else in the early game for the first 3-4 minutes except maybe a T1 mortar which could be added? You can also got another RE for even more capping which really helps USF rush out their tech. Rifles keep the enemy contained while your RE do all the capping. Besides the topic is about Riflemen Vet 3, not the early game.
It's easy to say "Use combined arms" but that's not the problem. And I really don't buy the idea of "It costs more so it should get better veterancy then X unit". No, each unit should have its veterancy made specifically for it that allows the unit to scale and be better at its intended role. Said veterancy should also not break things. Everyone remembers terminator Volks and how much hate they got. That should show no infantry unit, especially base infantry unit, should be near invulnerable to small-arms, especially when they have 5+ men. I'd honestly modify Ober vet to be a little less ridiculous at vet 4+ to be honest as that's how insane they are. Conscripts can get away with being hard to kill as they don't have much firepower and instead rely utility and being meatshields.
The main issue here with Riflemen is how high their received accuracy is and probably Rifle Company as it makes for a very stupidly durable flamethrower squad which is a big no-no, though that's a different topic.
Here's what Rifles get for survivability:
(0.97 Base x 0.77 vet 2) x 0.8 vet 3 = 0.5975 (round up?)
Hopefully got the calculations right, but that is pretty high for a base unit with good firepower. I would tone it down a tad more to maybe 10-15%. Or we could find more interesting options like reinforce cost, ability cost or other thing locked into their vet.