+20% attack for tier VII fighters (Upgraded T7), +30% attack for tier VI fighters (Upgraded T6, stock T7), +40% with tier V fighters (stock T6 carrier) with Dogfight (who picks that when there is torpedo acceleration?)...
The 20% bonus for both US and JPN tier VII fighters would bring their firepower level to almost on par with the F4U-4 and the additional 10% from first slot mod (aircraft guns) should slightly surpass an unmodded Saipan...A full fighter spec Tier VII Ranger will have its (upgraded) fighters' performance be nearly comparable to the F4U-4 in a straight fight, the Hiryu falls short in survivability. Alas, who plays full fighter spec?
Can quantity prevail over quality? A battle between fighters with comparable firepower will be decided by survivability...and the F4U-4 has plenty of it, but with only 3 planes a squad (4 with Air Superiority, consider that it has a real possibility to be so as a very experienced commander can be immediately assigned to the Saipan), how is it going to turn out? In a straight fight, that is. I think that the F4U-4 can kite the other fighters and chase down bombers with ease at that tier with 178 knots, and the bombers will have a hard time shaking them off with all the survivability the F4U-4 have.
...now one problem remain: Does the Saipan get the third upgrade slot for combat performance?