Gosh! Ifs and buts, and that's just not Cricket.
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No, it is needed. Because, not every time 7 world class batsmen are going to pile up scores over 300.
if those 7 world class batsman together can't score over 300 or near 300, then it clearly implies that no team can score that much.
India again scored 300 against England in first ODI without 3 World Class batsman.