You sir, are correct. I just read several articles and it seems my glutes are weak! I'm not sure how this happened!? Do you have any suggestions for glute specific exercises? I was able to reach a 500 pound raw squat and 585 deadlift before noticing any pain in the hip flexors. I've always squatted deep and figured that would target glutes. Should I perform sumo or conventional deads?
The glutes work through various planes, and so constructing a plan around that would work. Compensation games take a while before you start to notice issues, and it is possible to still be strong yet not utilizing your muscles effectively.
Stick to the Deads you typically do, but rotate in some other glute work as well.
Glute activation drills with progressions work well before you get going (things like banded glute bridges, hip marches, side lying abduction and adduction etc). These are for activation, and so you only need to do 10-15 reps of each per exercise for them to have an effect. Perform the reps correctly, slowly and through stabilizing the core. These exercises are difficult when done correctly as you should have no compensation movement (people tend to have weak cores and so they rotate through the spine during the movements, or compensate in other ways).
In your program, add in weighted adduction, abduction, horizontal and vertical glute exercises. Don't go OTT, just one per movement.
i.e. Banded Clams, cable adductions (or you could use a hip circle every once in a while), glute marches (progress to single leg only once you can adequately perform two legged ones), GHR, hip thrusts etc. just to name a few. The glutes work through various movements like Hip Extension, Hip External Rotation etc and so you need to work it in all those patterns.