>>720639292
I just think Miyu and Fay were ultimately victims of the fact that Takaya Imamura had very little to do with Star Fox 2, despite being a big guarding force for SF1 and SF64 and future games after that. Another dude at Nintendo, Masanao Arimoto, took over his role as SF2's character/sprite designer and he made Miyu and Fay after cycling through a bunch of concepts for avatars for the Light Arwing class, like the sheep design you posted, there were even humans and robots and shit.

Imamura's only known contribution towards SF2 was doing the initial sketch for Star Wolf which funny enough had Andrew instead of "Algy" like in the final game, which right there shows the change of primary character designer, and obviously when Imamura regained the wheel for SF64 he'd largely stick to his own concepts like re-reverting Algy back into Andrew and making his own cat and dog companion characters.

In a way it also explains why Krystal came in and "took their spot", because interviews reveal that Imamura's essentially the reason she even became a Star Fox character, Rare was initially just going to cut her out entirely in the transition from Dino Planet to SFA but Imamura who was a superviser/producer for the game requested she'd stay and he'd even help provide her final Vampirella redesign, claiming in hindsight that she was the character he felt the most attachment to from SFA's roster. It was also his call to bring her back in Assault, wanting to acknowledge SFA as a valid canon entry and also thinking that she was "enticing" in her own right.