We agree with the reviewer that there is no easy answer to this problem. We now include a discussion of this in the introduction and cite Lynam and colleagues on this exact dilemma. In their paper, they discuss the Perils of Partialing (p.4, line 15), which is what you do when you control for the overlap. That is, one may be removing the reliable aspect of the self-report measures of aggression (when they are highly correlated) and remaining with residual error.
In my view, this manuscript will make a nice contribution to the literature.