Okay, a few points:
1. If those on the wiki didn't notice that Jack uses the pistol, then it isn't his initial strategy to use it. Even on my various playthroughs, I never noticed he had it. That means he usually sticks with his gauntlets, with half of its function being useless against Tony. Even in Pre-Sequel, where he more actively fights, he sticks to his gauntlets only. Even if he does use it, great, it's a pistol against a guy who is experienced dodging bullets from multiple angles.
2. Jack uses his grenades like landmines, that's why the red sphere appears around it, so he's most likely not trying to stick Tony with it. Again, even if he does, Tony won't just stand still and let it happen.
3. J.A.R.V.I.S actively scans through the suit, even on things that aren't immediately in Tony vacinity (F.R.I.D.A.Y in Endgame noticed Ant-Man's van started even though he wasn't near it or actively paying attention to it), I don't think invisibility plus the clones will affect Tony for very long. It's also entirely possible for him to hack Jack's shield, clones, cloaking watch, loaders, turrets, and surveyors at any time.
4. While the AP advantage is quite a bit, it's not in one-shot range and Tony can call in pieces of the Hulkbuster to repair it. He can even summon that cage to hold Jack for a minute.
5. Jack is defeated really quickly once his shields are completely gone and he has no surveyors, his physical durability is garbage, so one hit from Tony after those are gone and he's dead.
As much as I love Jack, I still think his low experience and Tony specific tech advantages of scanning and hacking will result in him dying.