Its not entirely unlikely I suppose.
Remember, Namco have made arcade games on the Naomi hardware (Ninja Assault), and most people would see Namco and Sega as rivals.
Capcom and SNK probably had a lot of mutual respect for each other during the golden era of the arcade, and personally I'd have liked to see something like Metal Slug running on the CPS3 hardware.
Mabye if they had developed on each others hardware we would have seen a more accurate, balanced Capcom vs SNK, as they would better understand what goes into the 'feel' of each others games.
Well, mabye.........