I'm currently working towards doing 10-15 full form overhand grip pull ups at slightly wider than shoulder width. I can only do about 1 of them per set while keeping proper form. I can do 7-12 with proper form using a purple resistance band (12 in first set, then slowly dropping down every set to 8 at failure. However I can do about 3-5 neutral grip pull ups at less wide than shoulder width.
My question is, if I want to achieve the first thing (10-15 overhand), will I benefit more from doing 3x5 reps of neutral grip with full weight, or 10x3 with purple resistance band? I'm 135lbs and 6'2. Also when should I opt for a lower level band to hold less of my weight? I have been doing the resistance band ones for 2 weeks now and I improved from being able to do 7-8x3 to the 12-8x3 but i'm not sure if that's the best improvement I could have expected.