I am not sure how old Hayate is, but John'll be 15 in a couple of months and is always up for more bros. Plus somebody mentioned Hayate to him last month and how it was weird that they hadn't met before since they've both been here for a long time and apparently both talk a lot. I'm canon blind, but just going off that blurb you wrote there, Hayate and John seem to have a similar temperament so they might hit it off pretty well?

So if that's CR you'd be interested in, I am totally up for it! They'll both be at the breeding con so it might be a good place to make it happen. :D