What I meant is that it is nimble for it`s size and weight, not nimble as the A6M Zero.
In his weight class it's still be the sluggish as hell. As you can see A7M Reppu ( not Reppan ) don't posses that kind of huge intake, non radial have that. Radial engines create big drag, if you ad something that big to the bottom of plane you will have huge stability problems. It will only fit for high level bomber interception but if he go tango with enemy fighters, you are dead in boots.