Why such an unrealistic condition for modern era players?
Ignoring minnows , here are
entire history of test cricket with sub 25 avg with 300 wickets.
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Not a single bowler in this list played all 3 formats let alone being top dog in all 3 formats.
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As far as stepping up in ICC WC games is concerned
Entire history of ODI WC - Cutting it off at Wasim intentionally to avoid making it too long and he was one of the best all format bowlers.
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In T20: No need to list anything, he is simply the best bowler in history of T20.
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Looking at this, asking for 300 tests wickets at a good output and winning another ICC WC is not too much for qualify as an ATG?
One format specialist like Marshall never did much in ICC WC - He is an ATG.
Handlee never won ICC WC for his team - He is an ATG
Donald never won ICC WC for his team - He is an ATG
Steyn did not win ICC WC for his team - He is an ATG
Wasim himself has ordinary record in WC outside of doing well in one final. You will be left with McGrath. I don't think we should be saying that unless you are McGrath you are not an ATG. That's too harsh a criterion.
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In all 3 formats, he is alone at that level. But it will be unfair to discount players who played before T20, but we can see that we have just
5-6 pacers in history with good all around record in longer and shorter formats both.
Bumrah is one of them.
If what you asking - 300 test wickets and one more ICC WC. if he does both at a good output, He will then go down as the best pacer in entire history. Worse case, the top 2-3 pacers with a bit of decline. That can't be a realistic cut off for an ATG.
Longevity is fine to question with 100 test wickets. But if you produce Marshall like output with 250 plus tests wickets and be the among the best in other two formats, then you belong in the top tier. If he calls it a day today then top 3 all format pacers in history and in tests much below.