If you have your scoundrel a bow with +cold damage, and have him learn multishot, he will shoot fast enough so almost all the mobs you fight are slowed indefinitely. Works better if bow has +ias
This synergizes well w/ a dh (if u dont use cold arrows, or have +cold dmg weapon) or a sorc (if u dont want to use blizzard)
Probably good for wd too if they kite