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

This is the Dreamcast version. I copied the exact same boxes from above and pasted them onto this screen shot. You can see that the Dreamcast version is slightly squished horizontally, but the character heights are the same.

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

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