As far as Collingwood are concerned I am aware they rotate Davis and Didak through the middle for spells and both are good users of the ball but I wouldn't say they are true midfielders. That really applies to Thomas as well at this stage of his career. Pendlebury is by no means a one man band. The likes of Swan, O'Bree and Johnson (who I think has really come on as a player) work really hard to put him in a position where he can make the right decision.
Davis spends more time in the midfield than Johnson. O'Bree, Pendlebury and Swan are our permanent midfielders, Davis spends the next most time, followed by Didak (forward), Johnson (half-back) and Thomas (half-forward). I have no evidence of this, just my observations from watching all the games. Obviously the young guys like Wellingham, McCarthy and Cook get runs through, and so does Clarke, but not as much as the others.
So I'd rate us as: Fraser / Pendlebury, Swan, OBree, Davis, (any one of several, take your pick).