Glenn Johnson will make anybody look bad. People forget that he, not long ago, beat Tarver and Roy Jones, and he's had arguably more undeserving loses and draws than any other active fighter.
Dawson is incredibly talented - puts his punches together well, decent pop, high work rate, works that body, throws nice combos, but hes VERY hittable and has AWFUL recuperative skills. That being said, Dawson has shown enough heart in his past few fights that despite his suspect chin, he can still win despite being badly hurt against top level competition. Glengoffe is about as tough a fighter as it gets, yet Dawson still managed to survive the onslaught and squeek out a close decision. (I thought Dawson was gonna get TKOed after the 4th round, yet he managed to get his shit together - until he got wobbled late) Barring Tarver pulling a huge punch out of his ass (which admittedly, he has done more than a few times in his career), I expect Dawson to beat that ass. High work rate, and accurate punching will wear Tarver down. If Tarver does manage to hurt Dawson (which he most likely will) I don't trust his finishing skills either. Dawson has shown more than a few times that he can weather the storm (despite the fact that he looks awful when he gets hurt) Don't forget that Tarver has suspect stamina and has struggled with the likes of Elvir Muriqi and to a lesser extent, Danny Santiago in recent fights. Dawson struggled against Glengoffe, who's about as tough as it gets, so there's really no comparison.
Glencoffee is awesome, at his age he is still a force! I saw DAwson out boxes milkdud to a UD Woods is a total bum so Tarver did what he was supposed to