I think 4 day split is golden. 2on 1 off, 2 on 2 off
Legs day 1
Chest/Bi day 2
off
Back day 3
Shoulder/Tri day 4
off
off
For size gains I would recommend no more than 15 sets on everyting except arms and you only need 9 sets for each. Pick compound movements, Squat, bench, deads, overhead...