I'm not quite sure what you're describing, but I'm assuming that you mean there's some overlap in your gearing, so that (just for example), in your big ring and second lowest rear cog you have a gear ratio that's very close to what you have in your small ring and fourth highest rear cog.

Since you're at the same cadence regardless, neither ring is "better for cadence." The gear that's better is the one that gives you a straighter chainline, which puts less lateral stress on the chain and less rubbing on the teeth. Look down at your chain and see which way is closer to parallel to your frame (not the chainstay, the main triangle).