I guarantee you that one or two oar boats on nearly every trip have someone running the raft who is keenly into fishing. With the outfit I used to guide for at least four of us brought our gear on every trip and would use it as much as possible. The Middle Fork is usually pretty easy fishing but I actually had people fighting over who would get to go with me on some days.I don't know anything about the Smith, but if I wanted to fish the MFS, I would go with one of the Helfrichs
They cost more than mixed rafting/fishing outfitters, but if you really want to fish, these guys know fishing, know the Middle Fork and their focus is on fishing. With trips that are primarily rafting you might get a guide with some fishing experience, but from what I've seen, not much. Fishing is an afterthought to them, You will also be in a drift boat instead of a raft if you go with a fishing outfitter.