No. Because even if someone has more “weapons”, it doesn’t mean they have the right mentality (tactics, strategy, etc) to know when and how to use them. And a perfect illustration to this is when you compare players like James Blake and Roger Federer. Two players that were of a similar age, similar size, have very similar weapons, similar athleticism, and similar speed. Federer has an amazing forehand, Blake has an amazing forehand. Federer has a really good one-handed backhand, Blake has a really good one-handed backhand. Federer has amazing footwork (slightly better than Blake), Blake has amazing foot speed (slightly better than Federer). Both of them can serve between 125-130 mph, both of them had great second serve returns. Yet one is a 20 time grand slam champion and the other only ever made it to the quarters.
Despite having similar abilities, Federer is objectively a much better player than Blake. Why? Mentality. Federer plays with variety, Blake does not. Federer employs strategy, Blake does not. Federer varies his spins and changes the pace, Blake is a ball basher who goes for broke every shot. Federer relied on serve placement rather than serve speed, Blake did not. Federer maintains control of his emotions, Blake does not. And perhaps most importantly, Federer was physically conditioned and prepared to play for 4 hours in a 5 set match, while Blake never was. And that’s how you can give two players almost identical weapons and prove that one will be able to use them in ways that compliment his game, whereas the other relies solely on the weapons because he has no actual game. (Edit: not to take anything away from Blake; he actually had some game, it just wasn’t enough to win majors).
So giving Isner Wawrinka’s weapons won’t mean anything unless Isner were to transform his entire game around to be a multifaceted player. Moreover, Isner’s biggest problems are his lack of speed and mobility, which translates to having zero defensive game. The fact that he has no defense, means that he still only has HALF of a game. Andy Roddick has basically the same weapons that Isner had (with the addition of having a slightly better defensive game, and a bit more variety from the baseline). It wasn’t a huge difference, but it was enough to get him a US Open title and make it to 4 other grand slam finals before running into Federer.