All of these exercises work well for me, provided you are lifting with the rear delt. If you aren’t sure you are feeling them well, stand in front of a mirror with a smaller resistance band and do slower Pullaparts. Try to focus on feeling the tension build there in those muscles as you draw your arms apart to your sides. You can also see them working if you turn to the side and wear a cutoff/tank top.
As you get more comfortable pulling with the rear delt and keeping the lats and traps out of things, try it with dbs, cables or reverse pec dec with more aggressive resistance.
I always like ranges of 12-25 reps per set for 3-4 sets 1-2x a week. They respond well to volume and lower reps usually makes it harder to isolate.