A complete revamp is what Pocchetino did in Chelsea. Am happy he was man enough to let go of unnecessary players that were in Chelsea making no impact in the club.
I don't think it is complete revamp. There are several old players who stay in Chelsea, not every old players to be sold. Pocchetino seems to keep the players who still can contribute well and they fit with Pocchetino's tactic/strategy. It will be too risky if Pocchetino really take the option of complete revamp. Chelsea squad probably lose their balance and Pocchetino will be difficult to rebuild the squad quickly.
Is it up to five out of the several old players you believe Chelsea still has? There are currently only four older players left: Thiago Silva, James, Kepa, and Chilwell. When Pocchetino took over as Chelsea's coach, many were sold.
Inasmuch as Pocchetino has let go of so many old players, I don't think it's a risky move. He is simultaneously bringing in new players and letting go of old players, To balance the equation