There are 101 variables so we can't say if it's too much or not enough. No fixed number of sets/volume works for every person. If you are not getting the results you want the simple answer is to change things. Do you train calves?
I usually train all my legs once weekly. But I will also do hams and quads with upper body through the week too. I train calves pretty much every day I am in the gym. My calves are really responding well (for me) to 40-20 reps and approx 10-15 mins per day.
I could spend 10 mins to 2 1/2 hours on legs so it varies. Although when training all my legs it's usually 40 mins to 150 mins. That will depend upon my current feeling, goals, diet, what I have planned the next day etc etc. You would laugh if you saw what I done the other night for legs... your workout above x5. Although in general terms I think lower volume and higher frequency works best.
I find limbs (legs and arms) generally respond best to higher reps. But that doesn't mean low weight... as heavy as possible. Don't have a set number of reps in mind for your workign sets and truly go to failure when you can. Try some new things such as high reps (25+) really focusing on form and feeling the muscle work for every rep. Don't just try and get to the rep number... fail when you truly fail.
Rotate things but I like to do calves, hams and quads in that order. Add things like ab/adductors too for overall development.
Volume is not that important as long as when you are in the gym you effectively work the target muscle and truly go to failure using progressive resistance over time. Although most of the guys I know with freaky legs really destroy them with very high volume. So try higher volume and then try lower volume in the future... mix it up.