Back is a lot more complex and contains many more muscles than the pecs, so you naturally need more volume for back than you are getting for chest. Check the muscle anatomy charts on exrx if you want to learn more about it.
High-bar back squat (2 sets)
SLDL (2 sets) (or should I limit this to one? back fatigue shouldn't be a problem since I'm gonna do seated rows, just in the e-book there is one set of RDLs)
Flat bench (2 sets)
Incline Barbell Bench (1 set) (or two since I'm doing two sets for both major pulls? Or should I drop one of the pulls?)
Neutral Grip Lat Pull-down (2 sets)
Overhand Grip Seated Row (2 sets)
Standing Barbell Press (2 sets)
Upright Row (1 set)
Curl Variation (1 set)
CGBP/Skullcrushers/Any tricep isolation (1 set)
Lateral Raises (1 set) (Even necessary? Should I drop this?)
If you think you are good with the volume, do 2 sets for squats, 2 for SLDL. The second set won't be hugely important during the 15s but later on, I would definitely do it. No reason to do incline bench and flat bench though. If you want to pair a second pec exercise, choose dips rather than incline bench. All incline does is reduce how much load goes onto the lower pec, contrary to popular opinion that it increases tension on upper pecs. Incline does shift some load to the delts though, so it can be useful for that. However, flat bench - despite the bad rap it has gotten for destroying shoulders - is a solid choice. Make sure you have proper technique in bench as it is critical.
Don't do lateral raises for a core lift. You can do it for metabolic work in the 5s but there is no way to maintain form on heavy lateral raises. Make sure you add in some metabolic work during the 5s. I prefer seated dips for pecs, pulldown for back, leg ext for quads, leg curl for hams. Don't really need metabolic work for arms though you could do pushdowns for triceps if you want. I would consider keeping the bicep isolations as 15, 10, and 8s instead of 15, 10, 5 or dropping curls altogether in the 5s. Close grip bench is okay to go heavier on as long as you are careful. Upright rows aren't really necessary. The delts are small muscle groups, they don't need to be hit from every angle when back plus chest exercises paired with military press will hit all three heads. I wouldn't rely on upright rows for upper traps. Deadlifts and rack pulls will give you traps faster. If you really need to focus on traps, add in some barbell shrugs. One set is good enough and less risk of injury as your RMs increase than with upright row.
So here is what I would suggest:
15s and 10s
Squat x 2
SLDL x 2
BB Flat bench x 2
Weighted/Assisted Dips x 1
Pulldown x 2
Row x 2
Military Press x 2
BB Shrug x 1
Something for curls x 1
Close Grip Bench x 1
During 5s:
Squat x 2
*Leg Ext using 15 RM load for one set of 12-15 reps
SLDL x 2
Bench x 2
*Seated Dips or Assisted Dips using 15 RM load for one set of 12-15 reps
Row x 2
Pulldown x 2
*Pulldowns using 15 RM load for one set of 12-15 reps
Military Press x 2
*Lateral Raises using 15 RM load for one set of 12-15 reps
BB Shrug x 1
CGBP x 1
