I looked at new mods and found a very good mod on the theme of GTA V.
Now you can switch between 3 characters.
Between Tommy Vercetti, Niko and Claude, or Michael and Trevor (Franklin could not be added. According to the author, the game starts to crash after adding him).
Setup (to control Tommy, Claude and Nico):
files: army.txd army.dff Fam1.txd Fam1.dff Fam2.txd Fam2.dff add to gta3.img.
Add a file with the .cs ending to the cleo folder.
J - to control Niko. K - to control Tommy Vercetti. L - to control Claude.
Installation: (to control Michael and Trevor).
Files: Fam1.txd Fam1.dff Fam2.txd Add Fam2.dff to gta3.img
Add a file with the .cs ending to the cleo folder.