When they start beating on you, the first spell to cast isn’t Root, or even Mez. It’s the Color Flux line of spells. They stun everything in a small area around you. Each one has a different duration and cast time. Choose your favorite!
After that, you can cast a mez or root.
Between your color stun and your mez, of course, you would use your
GCD to eliminate the delay between spells. Man, who wrote that article?