Some sprites are busted, and that's 100% accurate to the game. Examples include Ogremon (dot394) and IceLeomon aka Panjyamon (dot409) which both have lime green leftover on them. Both these errors can be seen in game.

Additionally there is what appears to be repeat sprites. This is also just true of the game. For the most part boss entity NPCs use the same sprites as their non-boss versions, but nevertheless use their own slot, which leads to multiple copies of the same sprite with different names. The one exception I've noticed is Breakdramon (dot879) exists in both app_0 (main file archive) and the patch archive, and are the exact same file both in name and content. Unless I somehow copied a single duplicate sprite to one of my source folders this is also just how the files are, so I've included it for completeness.