Roy and Greg, thnks for your advice on this. I have been advised by a pond
shop that it would be easier to have separate small pumps for each fountain
so this is what I think I'll probably do.

Eh? A manifold should work just fine; personally, I think it would be
more convenient. Worrying about the friction loss is secondary. That
simply means your one pump may need to be a bit bigger than you expected.

C//