Stocking 6 inch HSB with 3-4 inch RES and HBG will not be a problem from a predation stand point. There will need to be food for them all in addition to supp feeding. I would suggest you first put in FH (20 lbs) and some spawning structure for them.
20 lb of FHM in a 1/4 acre pond? gulp - maybe I need to recalculate my plans...
HSB will eat all sizes of FH and RES and HBG will eat the fry. In my opinion 20 lbs of FH will last about 2-3 years by which time the pond will be established. In addition you could add a few bonus SMB as well. The RES and HBG will add little in the way of forage with the HSB and HBG being put and take. If you are going to feed extensively then this all changes. Without the FH you have no reproducing forage except for small amounts of FX HBG and some RES.
You could put in fewer FH and wait for them to reproduce or add more later but the second becomes expensive.