How long does it take to form a hierarchy?

So I've had my two male chins home now for about 10 days. A pink white, Bort, and a very dark ebony, Funzo. Both have settled in really well and have really gotten used to me, both very curious and will come sit on my hand when it's in the cage (but don't like being picked up just yet, working on that though!). They're both 3 months old and I've noticed them both a few times attempt to dominance mount each other. Neither takes too kindly to it but the dispute is always over within milliseconds and they're back to cuddling. Other than this they bonded great - the breeder did a great job with that as they aren't littermates.



My question really is will they ever work it out between them who is the dominant? They both seem to want to be. If they continue this behaviour growing up might I eventually need to separate them? I know there's always a chance of that but it would be a big shame just for the sake of being the alpha chin!