Yes, most people have more than one. I think they would get bored when they would be alone all the time.
Quite regularly you see a normal-sized horse that is kept company by a very small one - like a Shetlander. Those small ones are not as high maintenance as the big ones, and still they are good company.

I don't know what's up with the pics. Whatever I try, they always appear sideways. With my other phone, I just turned them around and re-uploaded them, but that doesn't seem to work anymore.
The weirdest part, however, is that if you click the image to enlarge it, it is showing like it is supposed to show.

I hope I can figure out how to fix it really soon