Help with secondaries

[Rpggames77]

I switched my main from sonic to Mario and have seen wonderful results. I play overall better and feel better about most matchups. The problem is the matchups I do bad in I do BAD in. My bad match ups are vs peach, zelda, fox and donkey kong. there are some that are okay but those are the worst. I can pretty much play anyone else with a few exceptions. Who would be a good secondary against these four?

 

[SushiKiller]

Fox and falco marth rob gnw tbh just learn the mu ur gonna be fine if u don't then just pick fox tbh he has few mus he loses