Chris - If you are asking if it's ok to add those 4 button bucks to a pen that has had 3 yearlings and a couple 2 year olds ''already'' in there together...put em in there.
I wouldn't have any concerns over that scenario, but don't wait til mid November to do it when the older bucks are all wigged out over the smell of does in estrous. Do it now Chris.
Will you have to sedate the fawns to put them in there?
And if you haven't cut horns off yet, add the fawns the day you do it...but of course AFTER you do it. The transition of new company might be softened a bit if those bucks wake up to them in there, not that the new company of button bucks is a serious threat to them...but they are new. (Murphys Law Chris, it will serve you well in the deer business to remember that one...just sayin)
Either way...I would feel pretty safe about it all...it's just that I've always errored on the side of being ''too safe'' whenever I have the option....if there is such a thing in this business of being ''too safe''.