This is the arcade version. I drew a box around Hawk and Ken.

This is the PS1 version. I copied the exact same boxes from above and pasted them onto this screen shot. You can see that the PS1 version is slightly stretched horizontally and vertically, so the characters appear slightly larger.

For reference, here are the other console versions compared to the arcade:
Dreamcast
CCC2
AE

Or you can check out a side-by-side comparison of all versions vs. arcade.