By skipping the Savo island battle, the IJN gives the allies a chance to land 11,000 troops and even some tanks on Guadalcanal! The odds of the Japanese overcoming this force s remote at best.
The IJN player must refight Savo Island and work to sink some transports. This cripples the Allies some and puts the TAC start in a more favorable position. The odds are still against the IJN , but this does give them a better chance. IF they can grab Henderson field, they again improve their odds.
The current rules do not allow an attack on the airfield in turn 1, despite Col Ichiki assaulting towards it in the wee hours of 21 August 1942! I suggest that you get your fellow gamer(s) to agree to allow this attack.
This with the potential loss of transports gives the IJN player a chance of getting a better outcome.
