you should sort out your left over troops before you even sell your ls really if u doint have enough general then you should transfer them ealier but the way i read and understand the OP he could sort his troops before he makes the last attack no need to remove the right of ls to click complete.
i personally always sort me troops either by transfering them back or assigning them to what generals i have before i make the last kill...
like fishslice said poor planning if you dont do this really....