Yup, That's the set they come in. On the bbts image they are 3rd from the left in both rows. The engine that replaces Rodimus' spoiler allows him to connect to BTS Optimus Prime Trailers. Also, that gun can flip out to look like Rodimus Prime's rifle and the engine piece can combine with it to make a big gun.

Added a bad pic of the combined gun, it's on the upper right side of the picture being held by Rodimus.