Naw,
_Chrome
already explained this and we've gone into detail about it on this thread before. ****ty matchups happen when characters have strengths and weaknesses. It's inherent. I didn't say ****ty matchups weren't a problem, but it's not something we can really solve; they'll always exist.
Especially not in this case since Tink's not even broken. Would you really solve the problem by changing the entirety of Tink's game plan/play style just because he wins against characters who are slow and/or have no way of getting past rang/bombs? It's not like he's even that commonly played. And he has his fair share of checks and counters too. Personally, I think the problem here is that Bowser is trash and needs to be re-worked or left alone and accepted by the community for how he is. And he doesn't win a bunch of MUs 90-10 lol. A few, yeah, but he doesn't outright invalidate characters because of his play style.
Edit:
Spralwers
Tink is a really good secondary for Marth for that reason. I'd have to agree with you about most of the matchups you listed too, except I probably wouldn't switch against Pikachu and I'm super comfortable with the Zard matchup (I find it super fun!), so I'm not sure whether or not I'd switch for him, even though Tink does do better than Marth in that matchup. Puff could go either way too but it's a lot less stressful to just choose Tink over Marth on account of not only how the matchup is played, but PM's large array of large stages to counter pick as well.