I don't think there's anything wrong with shoulder placement with the tattoos that you already have. If you were planning on building a patchwork sleeve I would have recommended you kept all of your tattoos on one side because having a single sleeve and no other tattoos can offer a really clean look.
Really the only placement that would look weird is if you got it on your hand and had no other tattoos. I feel like that makes you look like you're wearing fingerless gloves. Oh tattoos on the face when you have no other tattoos.
