I'd say honestly that Isabelle is a low tier character, probably one of the lowest. Without items, she's severely neutered and with reflect moves, the remaining half of her moveset is jeopardized or ruined. I'd put Zelda as "high middle class" mid tier.
Little Mac is balls lol
I had moved from my OG main, Ganon, to Jiggly and I was floored at how weak Ganon truly is. He can kill me in 3 hits but he is so slow, has so many lag frames, no shield to body attacks, and I can dance around him as Jiggly. At high tiers though, his short hop bicycle kicks are brutal in the right hands