It isn't that they are trying to zoom through it as fast as possible, but using sprint while grouping enemies puts enough distance between the tank and the mobs that they're unable to hit the tank, so it's not just a speed boost but also a mitigation tool. Then, once the enemies are grouped, its significantly easier on the party to aoe the enemies down while the healer spams their heals until safe to do damage. My advice to you is to keep an eye on your tank, sprint when they sprint, and stay near them on the pulls until everything is grouped up and move somewhere safe at that point. Don't forget to use swiftcast for a heal if you need to. Presence of Mind is also a huge help here.