We played a right winger (Jamal Lewis) as a left back for a few seasons.
Sorenson played as a LB so there was cover.
I use to have the view of rigidity as to where players played but after Lewis going from his normal right wing role to play as a left back, I feel there is more flexibility.
BTW. anybody remember Total Football played by the Netherlands international team?
As for McCallum, I suspect he has been playing further forward than a LB for Coventry.
As for Mumba, midfield, right back or on the left?