Add sub-rule to the rule “Sailing”:

Upside-Down [1st and 7th]: If any other rule is based on order of all Ranks and applies (in specific moment) only to Captains (two or more) of 1st and 7th Ranks (e.g. in battle between them), for that moment and for needs of that other rule these Ranks will be swapped (1st acts as 7th and 7th acts as 1st). If that other rule is based on only one of affected Captains’ Rank, no Ranks will be swapped. This rule of Rank-swapping applies only to situations of rivalry (e.g. selecting a winner or determining profits each Captain would gained) and not cooperation (e.g. sum of Ranks to achieve a goal).

This rule does not affect any existing rule, it’s for future.
I don’t know how to put it as simple as the idea is itself.