Mixing seahorses?

I'm mulling over the idea of starting up a seahorse tank as my newest project since multiple family members have been wanting me to stick some in my reef, but I feel as though that's out of the question with my current inhabitants.

I am curious as to whether I could mix a larger seahorse (or a pair) with pygmies, or is it best to keep them separated? I'd also love to keep a pipefish with the seahorses if at all possible! Can different species of pipefish be kept together?

I'm just curious as I'd love to get some variety in the tank!