Editing existing Pokemon vs expanding the Pokedex

[TalentlessNoob]

In getting new (gen IV and beyond) Pokemon into the game, is it considered acceptable or is it frowned upon to overhaul Pokemon that already exist into the Pokemon you want? What (if any) are the benefits and pitfalls of doing this as opposed to creating all-new Pokemon using G3HS or whatever?

I ask because in my planned "hack" (it's much more of an idea than it is a hack at this point), I want to keep the regional Pokedex relatively small - around 180 Pokemon or so, about 30 of them being "new". In Gen III that means 200 slots will go unused, plus all the additional Pokedex slots I would add. So it seems rather wasteful to me to jump through the hoops of creating all-new Pokemon from scratch, getting them to appear in AdvanceMap, getting them to function in general, etc. when I could just take pointless Pokemon already in the game, like Sunkern and Sunflora, and turn them into Snover and Abomasnow.

So yeah, is there anything I'm not seeing? Which is the better way to go?

 

[Dinoweed]

If you are only including 180 pokemon then there is no need to expand the pokedex just write over ones you don't want and then rearrange the pokedex number order.

 

[Christos]

Moving this to the Hub as it's more of a discussion thread.