The only real issue MG42s have against US is that the smokenades are just way too spammable. You don't need to aim them particularly well because they block MG42s from firing in a huge radius around the effect. Suppression rate, pin rate and damage are all good already, its only against sprinting units (hi conscripts) that mg42s have some issues due to gun traverse speed and weird targeting behavior around the edges of the firing cone. USF doesn't have sprinters.
You can't hold off an infantry blob with just an MG42, you need a forward spotter so it starts firing before the riflemen fire back at it (and likely instakill the gunner). But I don't think this is a requirement that needs to go away.
If you read carefuly what I've wrote you will notice that I am talking about MG42 in yellow cover supported by a Gren squad providing line of sight and blob of US Army approaching on the road and taking MG42 and Grens out despite being suppressed. If that's how HMGs should work for you than ok but form is that's not being effective.