Like when Hannibal said that if your back starts to round, your erectors need to be brought up, how would you know what needs to be brought up on bench? Squats and deads are easier to tell.
on bench find where your sticking point is and do board presses. like if yer sticking right after u start the push up, do a 1 or 2 board board press. it helps strengthen the area of the muscle thats used at each point of the press
i find bench is easiest to tell. if your max press fails at a certain point, then train lockout of the lift starting right below that point, and also keep up the accessory work