The last 3 hatches of RIR were only because I could see that I had too many roosters. At that time I think I had maybe 5 clear female pullets. Right now after all of the extended hatching I still have less than 25 females from this year's hatch.
I am in a similar dilemma. Mainly have more RIR cockerels than I have space to grow out. I've got 9 Reese line cockerels growing out (3/20-4/12 hatch) and 5 Reese line cockerels (hatched 4/27 and 5/12) in a separate pen, with some other birds that really need more space. I do not think I can combine those two groups of RIR males. The younger ones would be bloodied, I fear. I don't know, I'm almost ready to cull the younger Reese cockerels. I have 6 RIR cockerels growing out from another line also. I put a lot of emphasis on my Barred Rocks, Ameraucana, and Black Copper Marans this year and less on the Rhode Island Reds. As much as I'd like to grow them all out to pick through, I'm getting a bit stressed out over birds right now and the hot, rainless weather is not helping.