If I can figure out how to fit the other two starters in, then sure.
Erika can probably own the Venusaur, don't know who to give the Blastoise too though since Misty already has Vaporeon
Have Venusaur and Blastoise be region 2 and 3, but you get called back to the Oak Ranch to deal with them since they're also Red's. Then after region 4, you get called back again for a scene with all three.
