I think even in a 100 acre lake, the LMB will dominate the SMB and there will be little to no recruitment of SMB particularly in a Texas environment. Even lakes of 200, 1000 or more acres, LMB seem to dominate the fishery most of the time. Every now and again you do find a lake where the smallie dominates though, but they always seem to be fed by a creek that has a healthy smallie population to begin with, the water stays cooler and there is a cobble/bedrock bottom to much of the lake.
