In my experience if you have any type of status or maybe if you just get to the gate on time and ask nicely, it is better to be confirmed on the later flight and go standby on the 3pm. That way if anyone else has missed their connection, you're on, and if not, it's not the other way around--everyone on your 3pm flight trying to get on the 10pm and you just probably going standby vs confirmed. Just my opinion though.