You should never go infantry company in 4v4 to begin with.
If you single USF player, your purpose is too flood battlefield with infantry and play as aggressive as possible with it to create space for brits. So, rifle company, 1 rifle, 3 call-in rifles, grenades and flamethrowers asap. You should easily destroy your opponents with this build, always spread and always flank, use smoke to advance etc. If you on right side of lienne, you can also forget about existence of other tanks outside of e8s.
In case of double USF, airborne is always good choice to complement rifle co. Builds may wary, but my personal preference is double rifles, and ambulance to heal and reinforce them on the field. Then capt, paras, major and jacksons.
