MacArthur's father in a military command counterfactual

What happens if McClellan and MacArthur exchange their historical settings?

MacArthur could consult his father, whose military experience is treated as a useful source of advice in the imagined setting.

The counterfactual exchanges McClellan and MacArthur's historical settings. MacArthur could look up his father and seek military advice from him. His father's competence is the reason offered for treating that access as useful. The comparison therefore turns on an available source of experience in the new setting.