>>37597209>>37597742Johto’s pokedex has 256 pokemon, considering version exclusives, mythicals, postgame Kanto mons, not using the pokewalker, etc., Soulsilver has a roster of 227 available pokemon
Primo’s eggs give you Slugma/Magcargo. Murkrow, Kangaskhan, Cubone, Larvitar are available pre-national dex Safari Zone. Misdreavus and Steelix at Cliff Cave.
Houndour, Porygon, Chansey, Snorlax, Kanto starters, legendary birds, Ho-oh, Mewtwo, Mew, and Celebi are out.
9 of these are starts, so in a given playthrough only 218 pokemon are available. Let’s also assume you can’t trade, in which case 210 (Steelix can be caught).
Since you can easily get evolution items from the pokeathlon vending machines it is easy to get multiple stone evolutions, so nothing to worry about there. We'll assume there are no teams with duplicate pokemon
because I don't know how to calculate that Calculate the combination 218 = 139,081,484,934 * 3 for each starter line (playthrough in which you have different combinations available) = 417,244,454,802 theoretical teams taking into assumption there are no duplicates
