Pony Fantasy VI Remake

It worked, but in US now the sprites are glitched, so when I start replacing them, dunno how I'm gonna assign them molds without able to see how big they are accurately.

If the monsters are glitched before starting replacing them, it's probably something you did wrong when moving the data manually rather than a mold problem. Otherwise, a 64x64 monster cannot fit in a mold smaller than 64x64 but could fit in the 128x128 mold. Same is true for width and height taken separately (e.g. 32x48 cannot fit in 32x32 but 32x32 can fit in 32x48). Sizes can be smaller than the actual mold, meaning than a 24x24 will use the 32x32 mold or bigger but optimized one will be 32x32.

Don't some enemy sprites in FF6 overlap with no problem?

This never happens.