Fair theories and speculations so far.
Wonder what Ole's transfer strategy would be with United. Clubs operation, strengths of inherited team and financial muscle should be considered though since all three can effects manager's transfer dealings at top club United and small club Cardiff (and his other clubs, not sure) are totally different.
I doubt he totally follow the Ferguson way. I felt that SAF's way is an adaptation of the Busby way, SAF and SMB have totally different way in transfers and all. Similar in some sense yet clearly different. Anyway, the United way specific in transfers is not really that specific imo, just that there are some key criterias there, so it's more like a general way of the club consistent with the Untied way in other aspects (not all the managers after Busby including post-saf follow it). I bet Ole will only merely adapt some of the key styles of the Ferguson way into his own way.
Ferguson way, specifically transfer-in-strategy is more balanced though - he signed promising youngsters, promoted many youths, signed before-to-prime-age players, crucial good squad players, players that can still improve, ready-made superstars, and even declining veterans with huge exps that can still contribute. A nice balance really, with a purpose to mix 'em all up. Transfer-out strategy is to get rid of problematic no-longer-manageable players, and past-it players who just can't contribute anymore. His final last 3-5 seasons though while still maintaining the transfer in strategy but having problems with it and didn't solve it, his out-strategy unfortunately changes to keeping a lot of deadwood.
My speculating theory of Ole's way is, from the impression I got so far, heavily youth and young players oriented. So expect 18 to 23 y.o. players to join in. More youths breaking through, less players send out on loan, and more young players join. His transfer-out-strategy is more on to letting the useless players leave on their own willingly, while he will still give em' good comments and games to play, but fewer and fewer. In addition to his transfer-in strategy, he even convince/insist on Pereira (youth, young, promising) to stay, so he'll be convincing the likes of Pogba and De Gea to stay even longer as much as he can with his positivy.
Just a theory, can easily be wrong. Lack of info so far.
Would be a fun this summer getting to know Ole's Summer Masterplan (OSM).