Is it possible to replace characters in Melee with existing characters?

[Zacmariozero]

More to the point, I want to replace Popo and Nana with Luigi so it's a double Luigi team, but I can't seem to figure out how to do so. Tried using GCR, CrazyHand, and even ripping all the files, but no luck. Any tips to point me in the right direction if possible?

 

[SinsOfApathy]

More to the point, I want to replace Popo and Nana with Luigi so it's a double Luigi team, but I can't seem to figure out how to do so. Tried using GCR, CrazyHand, and even ripping all the files, but no luck. Any tips to point me in the right direction if possible?

https://smashboards.com/threads/hold-y-for-climber-clone-v1-2.452687/

Characters do a lot of setup based off the character ID, and simply replacing the file would cause a crash or other issues because of the loading method for the characters being individually hardcoded.