In a large air force, aka USAF, that may be able to afford a large number of F35s, I could possibly see an 8:1 ratio with some of the F35s slick and others carrying external stores.
I am slightly at a loss as to how a pair of F35s doing an intercept against say 16 4th or higher generation fighters will achieve a ratio of 8:1,
AFAIK all the F35s can only carry 2 AA missiles internally, so the initial fight BVR is won by the slick F35s then only if they are A's will they have a gun for self protection.
If the pair of F35s in the intercept are carrying external stores then surely they will be visible to the attacking fighters, so will be at risk of BVR attack.
Or have I missed a trick?