Bro Swift Vs FAW V2 make no direct comparison; look for their prices, safety / security features, suspension, <1300 cc engine in case of Swift so more taxes, >1300 cc engine in case of FAW V2 so comparatively less taxes, both engines are quite old / based on old tech, when compared to latest K series engines by Suzuki and latest 1300 cc engines by Toyota, etc. I think M13A engine in Swift does not even come with VVT.
Regarding sales figures, its a totally different story and depends on market dynamics, personal choices, and peoples' more trust in Suzuki as compared to FAW, etc.