I would recommend putting them in the same cage with a divider in between so they each have their own reasonably sized side. When I was bonding my two boars I did that for about two days. Rumblestrutting is normal. After about two days I would reccomend setting up a fairly sized playpen and put them in it together. It is normal for chasing and mounting to happen. I would also advise to keep them in there for about an hour or so. Only remove them if there is any biting and or bleeding. Then after that they should be fine to live together, my two boars took about a week or so to get used to each other, now they are inseparable! You might also want to check out the bonding articles on this forum, they are quite helpful. Good luck!