How can I train my rotator cuffs, posterior delts, lower,

Buy some of those big balls/sacks filled with sand and throw them around. Ranging from 1 to like 10kg.

Have you tried a barbell row

>>42725169
Like "wall balls" or whatever. Must be the most complete form of exercise. You train every muscle.
Throw them sideways upwards and you work the delts and traps like mad.

>>42724937
Face pulls, pull ups and different row variations

>>42724937
rc: shoulder external and internal rotation (probably do only external tho)
posterior diddlies: facepulls, reverse flies
lower traps: dips and lat pulldowns but only if you move the scapulae throughout their entire range of motion when exercising (try to push yourself out as far as you can at the top of a dip or let your shoulders come towards the ceiling when doing lat pdowns)

middle traps: reverse flies, scapular pushups

>>42725330
Thanks a lot senpai, this is a great help for me