I have always let the second fight call on a two-show day, be a decision made by the Fight Captain in conjunction with the actors who are part of the call. If any ONE of them wants to do it, it happens! Usually this applies only to a fight with very few actors and no swords or weapons. (And I must say, that this only applies when I have a great Fight Captain, with tons of past experience, whom the actors and I trust implicitly!) Larger fights and all weapon-play fights are done prior to every performance. Period.