I have had as many as a dozen sub-adult males together in a show tank with lots of cover and they got along fine.
If you have a female in the bunch then you get problems. Just take the female out, though it might be hard to sex the female until you can see her tube.
I have another 80 gallon tank with a couple very large EBs and several small EBs and they all get along fine, but I think they are all males.
The reason I am involved in EBs is because I like to see a dozen or so nice EB subadults in my living room show tank. When they get too large I remove the best for breeders and share the others and re-stock with the next batch of subadults.
You can do it. EBs are much less aggressive than JDs.