I believe Pochettino is bit like Unay Emery regarding tactical flexibility. One thing is for sure Pochettino like is players to be agressive, asphyxiate the opposition and you need to play a higher defensive line.
Regarding the Roles, you have two wingbacks ( WB(S) or WB(A) ) , Two central defenders with at least who is a BPD.
My problem with pochettino comes in the midfield. Sometimes you have a 4-3-3, sometimes a 4-2-3-1. With Eric Dier playing Anchor. Anyway with a 2 man midfield one goes forward the other stays.
One Forward ( CP(A) ) and 2 wide men ( mostly IF )