Therefore you haven't understood my post. Johnsen was bought from Besiktas, Stam from PSV, Rio had 1 CL season experience under his belt while Vidic was playing in Russia. None of these players had the experience to walk into United's first team let alone lead it but that's what they did, almost IMMEDIATELY. However they had one thing in common ie the necessary skillset to make it with United (ie they were good in air, they were physically strong, they weren't injury prone or slow pokes and they could pass the ball). That's why they were successful. The only CB Sir Alex bought because of his experience was Laurent Blanc. He was a mess with us.
Anyway United had struggled with CBs because after Sir Alex that formula had been ignored. Tuanzebe is injury prone and they lack inches, Lindelof and Rojo are neither physically strong nor good in air, Bailly is injury prone as well while Blind lack inches as well. Sir Alex occasionally tried to go against that formula and it backfired on him as well. Mickey & Berg (6ft) and Jones (5ft11 and injury prone) are good examples of that.
This obsession with ball playing CBs ruined us. Sure CBs need to be able to pass the ball successfully while under pressure (something Smalling can't do) but that doesn't trump over the characteristics a United CB need to have. An injury prone/short/physically weak CB is like a goalkeeper who lacks shot stopping skills. His passing skills may be top notch or he can lead the defence like Napoleon Bonaparte did with his army but ultimately he'll be fount out.
To conclude if Badiashile possess those characteristics I previously mentioned then he will win a first team place. If he's got ample pace then he'll walk into the first team almost immediately. Our central trio (Maguire, Lindelof, Matic) is simply too slow and two of those players are key players in our team.
LET'S FOCUS ON CHARACTERISTICS NOT EXPERIENCE.
Apologies for shouting.