Lexington and Enterprise give the sortie air power

Because Lexington historically left only shortly before the proposed sortie, advance planning could keep her at Pearl Harbor until the battle line sailed. Enterprise was returning close enough to rendezvous on the fleet's route. Together their task groups add six heavy cruisers and thirteen destroyers to a force otherwise short of scouts and screens. Some of those escorts could reinforce the understrength destroyer flotilla while older World War I destroyers serve as plane guards. In 1941 doctrine the carriers would operate ahead as scouts for a battle line that remained the fleet's principal striking center, rather than the later-war arrangement in which battleships screened fast carriers. That forward position supplies reconnaissance and combat air patrol while also making Lexington and Enterprise less likely to be caught in a Japanese strike approaching the battleships from behind.