Those instincts are hardwired, he will do what rabbits do.
Well, unfixed rabbits don't always fight, they are social animals by nature, that isn't snipped into them. Hormones can make things difficult, and two intact males almost never get along. But I have two pairs of intact does and let the buck live with one pair for 3 weeks (or as long as it takes) in spring.
An intact buck can stretch a spayed does patience to the breaking point (I have that pairing as free roam house bunnys), so it depends on the individual characters if it works or not.
It must be said that neutering and spaying them makes life a lot easier for pet owners, I even considered having Herr Hase neutered because of frequent "accidents" in times when his brain was drained of blood, and I felt sorry for Dotty, but then he got athrosis.