Willo's Deadzone completely negates Grover's ultimate, so a good Grover will avoid using it while you're nearby. Use this knowledge to help your teammates corner and kill him, but be wary of flankers because you're first on their hit list.
Dredge Anchor moves fast enough to hook Drogoz right out of the sky, and his weapons deal self damage, so hook him down and he's vulnerable to you and your supports.