In its heyday, Sega West was most definitely on par if you consider the difference in output because of the number of studios in Japan.
Sonic 2, 3 & Knuckles, Kid Chameleon, Star Wars Arcade, Etetnal Champions, Die Hard Arcade, Comix Zone were all great. Not into Sega Sports, but they did well and were critically acclaimed.
There was also Sega published editions of games like Lion King, Aladdin, etc., licensed games like X-Men, Jurassic Park, The Amazing Spider-Man vs Kingpin, and great second party efforts like Vectorman, Ecco, ToeJam and so on.
It also be noted that Sega West actually did a great job marketing in the 1990s, heavily advised against the 32X, protested the early launch of Saturn and built hardware that was passed over in favor of Saturn and DC. Sega Japan ran the company into the ground and then started digging.