derek, I agree, but none of these three hardly ever had to play an extended playoff schedule
In 12 seasons, KG has a total of 47 playoff games, just once beyond the 1st round (once to Conf Finals)
In 11 season, Ray has 37 playoff games, twice beyond round 1 (2nd, CF)
In 9 seasons, Paul has 37 playoff games, also twice beyond round 1 (2nd, CF)
The only extended playoff run came in 2004 (KG), 2002 (Pierce) and 2001 (Ray) respectively.
So I doubt anyone can predict how their bodies will react to such a heavy workload. Assuming they are in top conditioning it remains to be seen if this is enough to turn back time ...