I highly doubt f35 will use supersonic speed for anything else than repositioning/travel. In combat theaters i doubt it speed will go higher than Mach 0.8.
And anyway, if you want CAS, to stop an army, A-10 will probably be a dozen time better suited than any multirole, and especially the f35 with its ridiculously low availability rate, or even better in that particular case, an AC-130 (that is probably able to direct a drone fleet in its latest revision, but that was speculation last time i checked)
(the A-10 is the best modern plane in my opinion, i really like the F15, f18 and Rafale (those curves!), because i really like the idea of aircraft carrier but that plane is the best.)