I actually think a better sport for Neko might be something higher paced. In Yamatai in particular, I think they'd do really well with an IGPX or an F-Zero/podracing style circuit. I think racing sports, basically, where the Neko would depend on craft versus their natural speed and strength, would be more popular and get them to show off their "top of the line engineering" that makes them the fastest species.
Nepleslia would definitely be contact sports (basketball would fit them well, but maybe more like Slam Ball, where loose fighting and launch pads/trampolines could be used could make it more "Nepleslian).
It's something I've thought about, for sure, especially given that the two factions have such thick culture blocks but oddly miss the most simplistic peg of competitive sports.