Between the M107 and the M50, bottom tier matches for me personally haven’t been an issue. I’ve gotten 3 nukes in the T34, 1 in the M50, and 1 in the M107 this year so far. US gets plenty of heat slingers and heavies. Ironically, this is probably the BR where the US has the worst air MU’s in GRB because of the jets, but as soon as you hit 7.0 you’re back in business. It’s not as bad as 6.7 Russia where you’re still using an IL-10 for ground pounding, but it’s no walk in the park staying alive in the air here.
I do have the M6A2E1 and A-1H but I rarely use them in uptiers so I don’t think event vehicle bias is getting in my way.
Don’t rely on your hull armor. The M26 really is a bad medium tank with heavy tank mobility.
The big US super heavies are meant to snipe and fight hull down. However there are only a few tanks in that range that put the fear of God in me when they look my direction, the T29, T32, T34, and IS-2. All of those play about the same. If heavy tanks don’t match your play style then don’t play them.
6.7 is heavy tank heaven especially in midtiers and in downtiers which are common on NA server peak hours. The T29, T30 and T34 all lack some hull armor compared to IRL and their mantlets can be penned by the 122 / 88mm, making them dependent on a cover-oriented playstyle. The T26E5 has a worse gun but much more consistent armor.
So, I recommend pulling out your heavies first in downtiers. When uptiered, lead with a light, get some SP and then spawn a heavy once it goes late-game and people have used up their good tanks.
M50 is actually goated. 433mm of pen with more post-pen damage than any heat round has a right to and it gets the spotting+TD SP discount so you almost always get to follow it up with CAS if you want.
If you’ve got US air to the same level of research 7.0 is the better BR anyway since you get the F80A and F3D-1. There aren’t many people playing 8.0 either so you’re going to be playing the same matches anyway.