>>48617144Yeah. Rival has good coverage/typing, and up to that point the only electric type you might have is a freshly caught electrike, plusle, or minun, all of which does dick against Marshtomp anyway. That's definitely the best version of your rival's team since coverage is thin for Marshtomp too. Best way to cheese Marshtomp without handicapping yourself later is to get Shedinja.
In R/S you can cheese the rival (as well as most NPCs) with a Shedinja, but in Emerald all of the rival's mons have super-effective coverage for it, except for the most troublesome one, ironically.