Its all ifs and buts.
He's obviously impessed in an interview.
There isn't a definite correlation betweeen managerial success down there (or elsewhere) and with up here.
Brown, Smith, Jeffries, Burley and Levein (even Strachan latterly) all had a pretty tough time down there but have done reasonably enough up here.
Alot of it is down to luck and circumstance.
Personally I don't care about his previous as long as McCall can glavanise the team and get the wins in.