Heroes 3 Gigamight Resize modification resizes the creatures in the battlefield, making them look more proportional. HD mod compatible.
As a HMMIII player, I would say that it is a very nice idea which bothered me once too. Really, some creatures are not so comparable in size, and this development helps to feel the battles more realistic, especially if you pay attention that you sometimes have one Peasant defeating one Titan... but there is a strange number around 1000 or even 2000 at the Peasant's legs. Anyways, it's Heroes of Might and Magic.
As a HMMIII modder, I would say that some proportions are chosen wrong. The Troglodytes are too small and barely clickable, the Archangels should be much taller (otherwise they will be too small in comparison to other 7 lvl creatures) and there is no bad thing that Angels are taller than the ordinary humans, this does not really conflict with the majority of Angel concepts. The list can be continued further, but I will just say thanks for a good mod out there. Nice job.