Hey I realize the fight is kind of trivial and many people dont need help with it but today we discovered in raid a little trick. As long as your not going for the achievement on the two worms you can do this btw.
If you kill acidmaw first which I think most do once you get him to aroudn 5% wait until the next burrow I believe the mobile snake burrows first and you have a little bit of time on the one rooted we killed acid maw at this time. What this results in is Dreadscale not seeing acidmaw die and not enraging saving 50% more dmg buff he recieves.
Anyway hope this helps.