if you feed pellets and minnows get a little structure to hide out in when young, you could easily stock the YP and RES together. Ideally the RES would be a little bigger at stocking time so they might pull off a spawn in late summer next year, the YP would be a little smaller so they would target the pellets and the small FHM rather than taking a swipe at the smaller RES.
consider crayfish, a bunch of young crayfish are good sustenance for YP.
I also found that the FHM could not sustain in the presence of even a small population of YP. Consider strongly another forage strain of minnows or shiners. One that reproduces quickly and swims faster than FHM. It isn't too late to put them in your pond now, although they won't begin reproducing till water warms up next year.
If you can source them, I would strongly suggest spotfin shiners. They need special spawning conditions but reproduce rapidly and are hardy and speedy. They are outpacing my hungry perch and panfish easily. They also are murder on pellets even launching themselves completely out of the water as they go berserk for food.
