>>8651497>My logic is this, Fort Max is meant to be bigger than MetroplexThe toy is bigger =/= the robot is bigger.
Fort Max is a whole thing with me though.
Originally Max was just a large Transformer, who turned into a huge tank or troop transport. Then he went to Nebulos and became a Headmaster. Galen turned into his head, through an oversized exoskeleton, so his head was about two metres high and he himself about sixteen meters high (that's about two-and-a-half to three times the size of an average Autobot).
Of course, if we go by "Human-sized Nebulonian in more-or-less form-fitting armor turns into head" then Max is maybe nine meters tall.
Anyway, on the way to Earth, Max had his size increased so now Galen turned into the head of Cerebros, who turned into the head of Max. So if Cerebros is nine to sixteen meters tall, Max becomes either about thirty-six or about sixty meters tall.
Next step: after his human partner dies, Cerebros carries on and Max is upgraded again to become the guardian of Earth ('Car Robots') so the sequence scales up a step; Cerebros, who is about eight meters tall (he was shown as regular Transformer-sized) becomes the head of the Emissary, who is then about thirty-six meters tall, and becomes the head of "Brave Maximus" who comes out to about 128 meters. That's still pretty feeble really.
In IDW the 'real' Fortress Maximus used a headset to control a two-mile-tall Titan body. You'd need about three more intermediate steps to get to that size from a human-sized Headmaster.
Anyway... in my headcanon, Metroplex is just much bigger than Fortress Maximus.