Much of this discussion is beyond academic; instead it falls into the realms of fantasy. 1 x F35 will not face 50 MiG 17s (or MiG 21s). It's the same as the 'how many Spitfires could defeat a Typhoon?' discussions. Air Defence, (and counter-air) as any schoolboy (and Mr Noritake) should know is more than just fighters; do not forget the Air Defence Ground Environment (Radar and reporting, C3I, SAM, AAA etc), sustainment, doctrine, weaponry, training &c. Any inbound force would want to degrade the ADGE with defence suppression measures (ARM, ECM/active EW/cyber), possibly using LO UCAVs and Tomahawks, before sending in manned (legacy) platforms.
I'd like to see a flight of elderly, rusting MiGs (or Hunters, for that matter) try to operate against 4th or 5th generation fighters in the absence of a C2 system. In fact, I wouldn't. It would be a slaughter.