Not sure I agree with you there. Here's a few quotes from Neo-Geo.com reviews of Sengoku 3:
"Overall-9
This game is a load of fun. We need more beat-'em-ups like this on the Neo. At around the $250 price range on home cart, Sengoku 3 won't break the bank either. In this reviewers opinion, SNK and Noise Factory has answered Capcom's long line of beat'em-ups very well. If you enjoy the genre, Sengoku 3 will not disappoint. But don't get it for me, get it for Okuni" Review by SiFi
"Overall: With great control and smooth gameplay, Sengoku 3 delivers a short, but entertaining romp through modern suburbia while eliminating super natural creatures. It’s not great, but not bad either." Revoew from NeoLord
"This, rather than NitD, is the type of game which is needed to really revitalize the MVS in the way that it should be in this era of Neo-Geo games. Perhaps SNK was right when they said that "this is not just another Sengoku" (although an obvious marketing pitch) about this game, at it blows its predecessors away in every category. No, there is not a great deal of innovation here, but what is here is an extremely well done side-scrolling beat-'em-up, and, being devout Neo fans, given the hardcore 2D traditionalists we are, when all is said and done, Sengoku 2001 leaves us little room to complain. Overall: 8.5/10" Review from Yukuri