#I'm saying barring mirage because his legs are the relatively longest

[transingthoseformers]

Wait do they seem shorter because (most) of the autobots here have more humanlike upper arm/leg to lower arm/leg ratios

Like.

Barring Mirage, staring at Optimus here his lower leg is the same length as his thigh. With other transformers in other continuities, typically the lower half of the limb is longer than the upper half.