Ok with all the trials and errors i did with my different setups, i have the feeling that:
1- some games seem to work better on Voodoo1/2 than on Voodoo3
2- some work just fine on any Voodoo cards (like Hexen 2, work awesome on Voodoo2, 3 and 5),
3- some have a few problems on Voodoo3 or 5, but work just great on Voodoo2
4- Some games just don't detect later Voodoo cards and are "being detected" as "Direct3D card"

So all in all, i guess having different setups with different gens of Voodoo cards is the best.