Both adjustments do the same thing. The clutch cable is a fixed length. The cable housing length is "changed" (effectively) by adjusting in either place. People like to have theirs adjusted differently. I run mine a little loose, the lever has some slack when released. The only bad thing you could do is to take out "too much" slack and actually force the clutch to slip all the time. That would require going beyond the slack tho.
Use the adjustment on the engine to get it close, and use the adjustment on the lever to fine tune it. If the adjustment on your lever is adjusted way out, spin it back in and take up the slack with the adjustment on the engine.