Let's join forces, we've got our guns and horses

Maybe! If you're worried about your Hoppip getting hurt, you could always get something that's a little more compatible in size with your Vulpix. Shinx are pretty common around the beginning areas--if that's where you are--and something like a Buneary would be a good companion for the Hoppip.

[Let's just be thankful that the cute and fluffy things aren't eating each other as they technically do in nature, mmmmkay.]