There are three possible ways to grab an opponent's hand, wrist or arm: 2-on-1, 2-on-2, 1-on-1. The Cop's Russian and The Russian Tie are 2-on-1's, meaning that you grab one arm with two hands. A 2-on-2 is grabbing one wrist, cuff, elbow or bicep with each hand and that will be discussed in a later chapter.
Calm Down Sir is a 1-on-1 in that you grab one part of the arm, the tripcep with one hand. Hammergrip, Swordgrip and Scarbbardgrip are different ways of grabbing the writst with 1 hand.