It's not only size, but also design.
For example, if you take a look at BT mech drawings you will see that they were really varied. Comparing Myst Lynx to Nova is probably not good, because by watching BT picture, Nova can't really twist torso much. Also, side profile shows that total Nova's body size is probably still bigger than of Mist Lynx - much wider and longer. This was depicted in MW2 game, but changed in MWO. Nevertheless we don't know mech internals nor how Endo/Ferro/etc would affect such sizes, hence I will stay with those BT mech depictions. By the way, take a look at BT Myst Lynx weapon areas, those are real high mounts, almost cockpit level, while Nova's mounts are possibly lowest in game. Clean trade-off.
Then let us swap to BT Executioner, especially side profile. It has sort of backpack which most likely is artist visualization of Jump Jet and MASC carry area. If we would follow this route then you could probably blow this part of mech without killing it and it would serve as extra armor covering rear torso. Not possible in MWO(and also not exactly possible in BT tabletop). But lets look at the right arm, which is literally what one could call Shield Arm, with real shield on shoulder. In MWO this arm could be resized to make it really huge and extra Armor Structure quirks should be added to depict how different it is from left one. To compensate, left arm could be reduced and made really poor damage blocker, as it is already poor for Gargoyle. And whole mech should be smaller but bulkier of course.
Edited by G4LV4TR0N, 21 March 2017 - 06:40 AM.