What about if he faced all 3?
That'd be more complicated. We know that Goku could easily squat the 3 Ginyus, but that'd be a 66% difference or so. Dodoria is ~83% of Vegeta while Zarbon is ~90% or so and that, according to Freeza, would be enough to overwhelm in a team battle. 90% and 83% equals, more or less, 87%. So two warrios at 87% is enough against a 100%, presumably. Like I said above, I think 75% is plenty in a 2 vs 1 battle. Funnily enough, 75% is almost in the middle of Goku vs Ginyus and Veggie vs Zarbon and Dodo (66%, 75%, ~87%). So while 66% is enough to manhandle a 3 vs 1 scenario, I think 75% may be too, but it'd be getting the lion's share of Nappa's suppressed capabilities. A 75% is enough to deal with at most 3 warriors imo... and might not even be enough depending on the fighters.