USF does need a meatshield tank. The only problem with your suggestion is that there isn't a model for the Jumbo, unless Relic would be willing to use the model for the Easy 8 as the model for the Jumbo. I'd be happy with even a non-doctrinal Easy 8 (make it a side upgrade on Tier 3). If that happened, Rifle Company could replace the Easy 8 with the Pershing which would help that commander greatly.
Rifle company with a Pershing would just be a less good version of Heavy Cavalry.
Rifle Company could use a rework, but there is already a place for that. (Link below)
https://www.coh2.org/topic/92039/usf-rifle-company-rework