>>53614971IIRC Agumon normally evolves into the Tyrannomon (which has a more similar body shape), and only becomes Greymon if it has particularly high intelligence and fighting skill.
However, Greymon's huge body causes it to tire easily in intense combat. MetalGreymon is the result of it turning to cyborg enhancements to overcome this weakness. Originally this process caused it to turn from a Vaccine to a Virus type with rotting discoloured skin. However, it was later refined.
Combining the data of multiple Perfect-level cyborg Digimon (MetalGreymon's left arm and chest, Megadramon's upper head, MetalMamemon's cannons, etc.) produces the Ultimate-level Mugendramon (aka Machinedramon), which was one of the franchise's first "final boss" types.
Alternately WarGreymon is an optimised Ultimate-level form of the Greymon line that strives to the highest ideals of Courage, compacting its power into a smaller humanoid form. Its finishing move "Gaia Force" is an extension of the Greymon line's connection to Dragon Veins.
