One of my sons killed a bull his first year archery hunting at age 12 shooting a 50# bow with a really short draw lenght due to his size at the time. I think it was around 235 fps but never shot it thru a chrony.
I had reservations on buying him a tag but decided if he used a cut on impact (two blade) broadhead and held out for a perfect broadside shot at 20 yards or less he would be good to go. It worked out perfect! He double lunged a bull at 7 yards and he only went 25 yards and was dead.
I think your brother would be sitting a little better with his set up and would be just fine out to 30 yards as long as he chooses the proper broadhead that will provide good penetration. That is my opinion anyhow based on a personal experience. Good luck!