In nature they eat yellow perch among other things. Not sure if perch reproduction alone could keep up. I would think they would eat bluegill if there were no other choice even if their shape is not ideal.
I personally would go with Pike, LMB, perch and sunfish for a balance.
But, If you want only pike as a predator, maybe perch and green sunfish as forage since green sunfish are more slender than bluegill. That would be an interesting combo and the green sunfish fans may chime in!! However, as the pike get bigger, they are going to want larger forage than the perch or sunfish, probably.
How about Chain pickerel instead of pike? Similar in most ways but don't get as big
