You are in good shape. Bull are mostly in bach groups but will start sniffing around soon enough. if you get impatient look higher or the next drainage, the bulls wont be too far off.
I've been scouting 35 real close to 36. Same thing, lots of cows and small bulls, haven't been able to locate a bachelor group yet but they gotta be in there somewhere.
As long as you have cows located, those bulls will surely know where they are. Pre rut all we try to do is find female groups and then keep checking in on them to see what has rolled in as things get vocal.