Hopefully some of the 100 RES survive the 3# LMB. It may make snacks of them unless they are of advanced sizes. New small fingerling fish that may have never been exposed to predators put in an unfamiliar surrounding in water they are not used to are pretty vulnerable. Some should make it though.
When I had only RES and FHM in my forage pond, I noticed when I fed the FHM at least some of the RES came to the shore line where I was feeding. The way I knew is I discovered I would have much greater success at catching them with my cast net if I fed the FHM a few minutes before I threw it. Since the FHM could not swallow the larger pellets I was feeding, they would peck away at them till they softened up enough for some of them no doubt sank to the bottom before the FHM got them completely consumed.
So I am with NEDOC in that I think once they were accustomed to eating fish food pellets, perhaps pre-soaking them so they would sink they might be fed that way.
The problem in my ponds is that the BG are just voracious and most of the time I don't feed nearly as much feed as they would consume if I fed to satiation. So the BG (and hybrids) are going to get the feed way before it ever hits the bottom.
A little bit of additional information on RES
RES info and links to old threads