Flashes vs Galactus heralds

Barry
Wally
Bart
Zoom

Vs

Silver Surfer
Morg
Star dust
Terrax
.for this fight the Flashes get a Legion flight ring to go along with their speed, who wins and why?

Flashes 10/10

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What stops the power cosmic team from frying the rings? I can't see why the Heralds wouldn't be a serious threat here?