When Berbick stopped Big John Tate, if he earned an immediate shot at Weavers WBA title. who would have won 15 rounds.
See Weaver-LeDoux. Mike had the straight jab necessary to negate Trevor at range. Berbick did not have the power to trouble Hercules at that stage of Weaver's career. Beyond that, Mike's one punch knockout power in both hands could pose a serious issue for Trevor in the championship rounds. The best time for Berbick to get a shot at Weaver would have been in late 1982, before Dokes and Joey Curtis came along, and after Trevor's wins over Page and Racette. Even then, I'd favor Mike.
Weaver.When he had too, Mike could step up his game, Trevor would be behind, and either lose by a UD, or quite possibly a late round kayo.