As I said on the other thread, I would just put them all in together straight off. OK so they're entire, but they are too young to challenge a shearling tup. He may well chase them round a bit, demonstrate his dominance by humping them, but initially there will be no fighting. If these two are keepers, then at some point in the future they will have to fight to establish dominance, but usually the older tup keeps the top job until he's old.
It's very different when introducing older tups together, when however you do the intro you are likely to get jostling for position (in primitives anyway) for quite a while. Also putting several tups back together after tupping time when they'll all be a bit full of themselves. In both those situations we would pen them up very tightly together for several hours, then let them out to eat a little hard feed, plus get at the grass. To date, all ours have been ok on that regime, but there are no promises as all sheep are different. Sometimes they have fought a bit, but not usually for long. If you can bear it, leave them to sort it out. If you try to stop them fighting then they'll just wait til you've gone away then have their fight anyway. The Romans loved tup fighting, in fact it seems they imported multihorned Heb-type tups to Rome for the Games.