I agree that being able to commend more than one person would be nice, but I feel that is very close to making the whole system pointless. When you're commending half the group, why even have a player-based commendation system at all? Just have the system give it out for participation (note: I don't endorse this idea at all). A way to apply a multiple-commend system might be to have the usual commend you give out at the end of every duty, and have a daily/weekly alotment of bonus commends you can choose to use on extra players beyond the usual one per run.