A valve train assembly includes: a first group of one or more dual body rocker arms and a second group of one or more dual body rocker arms, the first group for controlling one or more valves of a first cylinder and the second group for controlling one or more valves of a second cylinder, each of the dual body rocker arms including a first body, a second body, and a latching arrangement for latching and unlatching the first body and the second body; and an actuator arrangement external to the dual body rocker arms for controlling the latching arrangement, the actuator arrangement including a shaft having a first set of one or more cams for controlling the latching arrangements of the first group of one or more dual body rocker arms and a second set of one or more cams for controlling the latching arrangements of the second group.