What starter will you be using zdrup15? If Pikachu solos the rival's starter without using Iron Tail or Hidden Power, you are pretty much limited to Normal moves on Marshtomp (because it is Water/Ground and you get Brick Break in Sootopolis), and possibly Grovyle unless you rely somehow on parahax or something. Then again Pelipper cannot learn Dive or Waterfall in Emerald, and an Azumarill with both moves conflicts your challenge since Raichu also gets neither of those HM's. The others are not Water-type, so either:
1) Start with Mudkip, so that the rival has Treecko/Grovyle, and have Mudkip Dive and Azumarill Waterfall or vice versa, or
2) Have Azumarill Dive for the Seafloor Cavern, then prior to Victory Road (which you need Waterfall to reach) use the Move Deleter in Lilycove to delete Dive for Waterfall
1) Start with Mudkip, so that the rival has Treecko/Grovyle, and have Mudkip Dive and Azumarill Waterfall or vice versa, or
2) Have Azumarill Dive for the Seafloor Cavern, then prior to Victory Road (which you need Waterfall to reach) use the Move Deleter in Lilycove to delete Dive for Waterfall