Advance's sprites are still my favorite in the series. SRB2 is a sprite based game, so I wanted to homage them from the beginning. In fact, some of my earliest SA Sonic sprites were me trying to emulate the walk and run from those games, but I wasn't experienced enough at the time and it was taking too long, so I just straight up traced the SA2 animations.
By the time I got to the victory poses, I knew what I was doing and was able to get the poses I wanted. Also, just because it's Adventure Sonic, doesn't mean he can't reference non-Adventure games, though I really want to avoid going outside of that era as a whole. In fact, I did have an Archie based Sonic color that I ended up axing because it was from the reboot era comics and that was way past the Adventure days, as much as really cherish the comic. If I am to go outside that scope, I might end up making my own crazy color pack or something.