I need to play against a Peach again at some point I guess, because when I played Fe it was never an issue... then again, instead of sitting in shield I'd just shoot lasers at various heights to try to mess up float and jump in with an aerial if they hit them. Benefits of being Falco I suppose.
Also, having a high technical barrier =/= not overrated - and c'mon Baby_sneak, I think you of all people would know that, since I believe (or maybe just falsely convinced myself) you play Fox in Melee (and know you do in Brawl-).
Also I often think of Nana as bait - if they separate and push hard after Nana you can try to smack them offstage and edgeguard them or at least rack percent - and unlike in Melee and Brawl, trading Nana being gimped for KOing them is a good trade, because one up+b and voila! She's back onstage. Their combo ability is underrated, at least in my opinion (Nana's dair has zero landing lag - I don't know how to use it but others apparently do, and their dair in general is great - late dair chains to stuff (actually late anything chains to other stuff with them which can chain if a good option is chosen), and uair strings at low percent, and fair meteor to tech-chase, etc.). But I can't play them all that well, so it's not like I can come beat you up and prove it.
They also probably don't like Fox (admittedly shine spiking Nana is now mostly just a joke, since she'll never be gimped that way unless you go SUPER low, but it still splits them up just fine) which helps your case.