One of the problems with the Brumbies is that there has been too much inbreeding. This emerged at the start of the franchise when it was us against the world (well, against NSW and Qld) in a contest for resources and respect. It was almost a Boer laager mentality with the wagons circled against the threats and motives of outsiders.
The players, inside the circle, were empowered to an unprecedented extent but it worked well given the astuteness and insight of Macqueen to directly it properly, and the rat cunning of his successor, Jones. They became the best Super team in Oz by some margin, but in recent years the old energising Brumbies precepts have become unproductive and even counter-productive.
Andy Friend was supposed to be a new broom but it didn't work out that way. If they can acquire Jake White they will get a guy who will get his way as he had to do in adversity in South Africa. Sure he hasn't coached since the 2007 RWC, but since his team won it he will bring a gravitas that will counter any second guessing or so-called player power, beyond that which is normal.
I'm guessing that he will pay particular attention to young players at any level in the Brumbies stable; nobody who has read his book would think otherwise.
I don't think you can overlook a quality candidate like Gaffney though....
Gaff has been around the traps: he's had the main job a few times and most recently at Saracens before Eddie Jones took over, but his main point of difference is his experience as a backs coach. I've heard talk that his ideas of back play are still modern and everybody seems to regard him well in that area. He was the Ireland backs coach in the recent 6N tournament and they didn't shine until the last game, though to be fair: the forwards weren't that great until that game either.
But he's 65 now, or close to it, and having passed that score myself I would be looking for a younger man. If anything, I would use him as a consultant to all the Oz franchises and their academies and the Under 20 teams. A few chats to mentor Bernie Larkham would be useful also.
If an Aussie has to have the pole position then I would go with Steve Meehan of Bath who is highly regarded despite being let go. I reckon the only reason this happened was because Bath are having hard times and there were paying both Steve and guru Sir Ian Mac, and after asking the great man, he consented to be head coach next year.
Cheika is in his first year of being coach at the nutty silver chalice club Stade Français, where his main job is to get all the deranged structures right and to pop downers into the mouths of his princesses before they run onto the park. Mind you: they won't be qualifying for the Top14 finals this year after their loss to Montpellier on the weekend; so he could get the sack and be available.