Hi! When I do splits I do 3-5 exercises per muscle area. When I was in better shape I would do:
Close Grip Push up (put your hands so you make a triangle with your forefingers and thumbs)
Overhead Triceps Extension
Lying French Press
Triceps Kickback
Side Lying Push-ups
But I can't even barely do one side lying push-up and the close grip push ups I do if I'm feeling exceptionally pumped up!
So right now I just do the Overhead Triceps Extension with dumbbells, the Lying French Press w/dumbbells or an EZ Bar, and the Triceps Kickback with a dumbbell.
Personally I really wouldn't do more than 5 exercises that target one specific muscle group. I do 3 sets of 8-12reps depending on the weights I'm using.
I usually only do 2-3 for my biceps though as they seem to bulk up really fast. Like a Concentration Curl and a Supinating Curl or I do a Hammer Curl and a Standard Curl.
Oh and one more "me" tip... When I do splits I do each muscle group 2x/week. Oh and if you wanted to do all those exercises you could do Half one day and Half your second workout, or do 1/3 of the exercises 3x a week, so you would be constantly challenging and your workout would be so varied you could probably do it for months without having to change it up. So hope this helps you figure out a workout that's suited for you!