I'm trying to focus on getting stronger and increasing work capacity.
Lots of guys do more than one hip and leg move in a session. No problems. Remember too, you can build work capacity, just by slowly doing more, even if it is the same exercise.
90% of the time, I always do a deadlift/scapular retraction move and a style of squat (usually back) in the same pos W/O. (and yes I alternate the intensity, so if I do deads heavy one W/O, I go lighter or medium on say squats and vice versa. )
If you approach it slowly (and do not make yourself sick of it by doing too much at first, then not wanting to try again) you can slowly over time build the capacity to do a lot of hip and back work in a single session. It is another reason too, that assistance exercises can follow the prime mover. ie: Back squats main work then, GM's, lunges, RDL's or any number of other ones.
" ?" When you say you are working with 70%-80% of you 5RM? do you mean you're 1 RM that you are doing 80% of for x5's?