Hypertrophy - gluteal fold & rep ranges

If it looks right then it flies right. Taking a look at my legs, it would seem like I have fairly well developed quads and large glutes, but I believe I have a gluteal fold from less developed upper hamstrings.

I’ve weightlifted for about a year, did a lot of squatting to a deep position, but it didn’t seem to hit the hamstrings that well… I think possibly because of the way I’ve performed them breaking at the knee first rather than the hip. I’m currently not doing any speedwork as I’m down and out due to shin splints, but I can still work in the weights room, hoping to be healed in 2-4 weeks so I can properly start GPP.

Basically, should I drop the squats and maybe do lunges and stiff leg deadlifts to try and get some extra hamstring development in?

Also, would it better to stay away from bodybuilding rep ranges of 8-12 and go for 4-6 to hypertrophy the fast twitch fibres?

as you said what looks right flys right but that does not mean you should seek the looks in expense of the performance. train properly and soundly in a manner that befits your goals and your body will take on the proper proportions. for example you are concerned with you gluteal fold, some of that is going to be genetic and the rest is most likly going to come from training hip extension movements. as a sprinter these movements should be a natural part of your training regiement. as for rep range i will say this train your muscle how you want it to perform. if you want slow bloated bodybuilder muscle then train as such with slow movements and relativly high reps. if you want to be an athlete your training should focus around teaching your nervous system to be able to recruit the maximal amount of motor neurons at the most optimal frequency and in a patterned control which best fits your athletic goals.