Wasim’s avg vs top countries during his era :
Aus - 24
England - 28
Ind - 27
WI - 26
SA - 39
Imran Khan’s avg :-
WI - 25
Aus - 28
NZ - 26
Eng - 24
Ind - 28
Both were mostly good everywhere but never stood out anywhere away from home vs a top nation, like Hadlee, Bumrah and Ambrose did in Australia.
IK, Wasim, Donald, Cummins and Rabada have been balanced test bowler, being fair weather bowlers who did well vs top teams but didn’t stand out vs any top team like Marshall, McGrath, Hadlee, Ambrose and Bumrah did. One may include batting for IK and then his case strengthens as he has won player of series in various countries. At the same time, Bumrah would need longevity/ durability which others have and Bumrah lags in that aspect.