This isn't advice -- so please don't take it as such...listen to those with more experience! I just wanted to share my experience this year, as I'm so delighted with it!
I had 3 bucklings born this year between Christmas and New Years. Their daddy is 3+ years old, and is pastured with a 2 year old unrelated buck. There is a "hole" under the fence between the barn paddock and the buck paddock that my LGD's created and use to move freely from paddock to paddock. Of course, it wasn't long before the little boys learned to use it.
What was so delightful, is that their daddy (senior buck) stood watch over them! He made sure the younger buck was gentle with them. Now that they're approaching weaning age, they're spending a lot of time over there, and everybody gets along great. (No, I don't feed them over there...I'm delighted, but not stupid! LOL)
Anywho, I will be keeping one of these boys as a possible replacement for his dad, so when I wean him I plan to plug the hole and put him over there. I wonder if my experience is as unusual as it is delightful?