I had to google karambit. Scary.
If I were advising you (which I guess I am?), I’d suggest making delts the primary focus of your upper-body days. You want to train 3 days/week; conveniently, the delts have three heads. Thus, you can give each delt head its own day of emphasis (cross-stimulation is inevitable, and not a problem), and build the rest of your workout around the delt work. For example:
Monday–Lateral delts
Exercise 1: DB laterals. 5 sets (not including warm-ups). Weight should allow you to work in the 12-20 rep range. Rest ~60-s between sets.
Exercise 2: Wide-grip upright rows (or snatch-grip high pulls). The rows can be performed with a bar, DBs, or cable. (SGHPs pretty much require a barbell.) Feeler sets as needed, then 5 sets of 8-12 reps, reverse-pyramid fashion. Rest 2 minutes between sets. On the last set, employ some form of intensification technique (drop set; rest-pause).
Throw in 4-6 working sets of the lat exercise(s) of your choice.
Wednesday–Front delts
Exercise 1: Shoulder presses. Can be done with BB, DBs, machine, bands, what have you. Seated or standing. Lots of warm-up/feeler sets, then 5 hard sets in the 8-12 rep range, resting 2-3 minutes between sets.
Exercise 2: Incline chest press. Gotta fill out that space beneath the clavicles. DBs or BB, your choice. Can also consider doing them hex press style: Tip: Build Pecs with the Hex Press
Same parameters as shoulder press (5 hard sets in the 8-12 rep range, resting 2-3 minutes between sets)
Throw in 4-6 working sets of the triceps exercise(s) of your choice.
Friday–Rear Delts
Exercise 1: Face pulls. Can be done with cable or bands. 5 sets (not including warm-ups). Resistance that allows you to work in the 12-20 rep range. Rest ~60-s between sets.
Exercise 2: Behind-the-back upright rows. These are best done on a Smith machine, but can be done with a free BB, DBs, or bands. Feeler sets, then 5 sets of 8-12 reps, reverse-pyramid. Two minutes between sets. On the last set, employ an intensification technique.
Throw in 4-6 working sets of the biceps exercise(s) of your choice.
Note that the days are Pull/Push/Pull; by grouping exercises in this manner, we lower the risk of an overuse injury to the triceps and/or biceps (voice of experience speaking here).
When children run away in fear at the sight of your cannonball delts and freaky traps, don’t come crying to me!