When the combiner was first teased as chibi characters, they included a chibi Optimus Primal with the crew. They also mentioned that the combined form wouldn't use "pants" like Toyworld Constructor or Zeta's Combaticons/Aerialbots. Yet the size is still the same as them. Speculation is The pelvis/thigh area will be a gorilla member. Personally I'm fine with a gorilla addition to the team if its subtle, especially if the choice is that or pants. I just don't want it the be Primal, would feel weird having a character from a different era , and an Optimus at that.