All I can say w.r.t Kapil is that he is one player who is soo under rated by many fans because of his plain averages. They just ignore the adversities
Kapil had to face thru out and also the highlights of his career.
Extremely weak support bowling, huge word load( first 62 tests in just 5 years, 3000 balls bowled before he turned 21 , never took a break despite injuries etc etc are some of the features of this factor , ) insane longevity, fair play( he never resorted to unfair tactics like ball tampering) all affected his end bowling average.
W.r.t batting , he was convincingly dominating than even the great Viv Richards( str: of 81-82.5 against Viv's 70), played many iconic back to the wall high quality innings, upped his normal batting standard against the mighty Windies in Windies( GOAT team) etc etc.
Add to that his ODI credentials, brilliant all round fielding , captaincy , he for me was such a high calibre all rounder.
He would be my 3rd or 4rth GOAT all rounder behind Kallis, Sobers and perhaps Shaun Pollock.