To get strong, pare your workouts down and focus on the big lifts. Ditch the variations.
If you can't squat 315 for reps, you probably don't need to be doing reverse band safety-bar box squats with chains using eleventy billion pounds. It's quite possible that you need to perfect your squat technique for your goals, and spend a lot of time, you know, just squatting.
The lifts will do a tremendous job of actually building themselves, especially once your technique improves. Trying to add variations on top of variations is a poor use of your time.
Strength has a large neural component. The more often you do a lift, the more efficient you become. The more exercise or movement variations you have, the less time you can spend in that neural zone becoming proficient at your priority strength movements: squat, deadlift, bench press and overhead press.
Pick the lifts you want to get good at and work from a standpoint of being a minimalist when it comes to exercise selection. If your strength stagnates and your technique is pretty solid, then ask yourself if you've been doing too many variations – or too many exercises in general – during training.