Yes, actually I meant center of gravity in the height dimension, to prevent either ship simply toppling. Sorry I didn’t make that clear. As for COG in the XY plane, yes, I guess you do want to impart rotation by hitting close to one end.
As for motion after it dislodged, if you perfectly estimate the work required, there should be essentially none. But if you over-estimate, then maybe the original ‘bank effect’ may damp subsequent motion, but anyway, I doubt it would set the ship infinitely spinning due to water resistance or a cable to damp further motion.