The thing with 'Fatimus Prime' is that the odd proportions were intentional to accomodate the Super mode, to make sure Super Optimus/Grand Convoy didn't have a small abdomen with fat limbs. One mode had to be sacrificed for the other. But in Inferno's case, there isn't a need for the blockiness, as there isn't a third mode, and as it has been seen in toys like Robot Master Convoy/Optimus, panels can be shifted to prevent the main body section being a straight usage of the blocky cab of the vehicle mode. I just think it looks lazy for Inferno, with today's engineering, to use the cab as his entire abdoment (the front bumper folds down, but that's basically it). Even the Gen1 toy had the cab as just the chest and stomach of the robot mode, with a separate piece forming the waist, which made it look taller, not fat like this one.