I think you should try adding the OSS and see how it goes, skip adding golden shiners. The lack of commercial availability of OSS likely means there isn't much information on how they might interact with SMB/RES/YP pond. I can tell you that a 13" SMB can easily fit a 5 1/2" RES in its mouth. If OSS can persist with LMB present then they should do fine with SMB and provide plenty of forage. I would much rather have a forage fish that doesn't get large enough to escape predation than one that can get too large. I've been waging war on large golden shiners in my SMB/RES pond for the last two years, a large GSH is a direct competitor with everything its size and smaller.