Frog, I've not found that to be true in my area of North Texas. The creeks seem to be full of GSF without a lot of bluegills and no RES.
In man made ponds they are usually introduced by man, mostly by hatchery mistakes. I had a bunch of them in one pond but over time, the bluegills just outspawned them and predation pretty well took care of the rest. At first, I bought into the bad GSF mantra and tossed them on the bank. Then I started noticing bent hooks and good fight and started liking them. Being more cylindrical than a BG, the bass seem to prefer them (I guess).
They seldom last more than 5 years in ponds around here.
A couple of years ago, the creek on my place got to my forage pond and I wound up with some GSF. When I seine, I don't sort them out. I've never found them to be a problem.
But, we are in vastly different regions.
