You are correct, it is a random draw; however when you link with a rider/owner prior to the tournament application deadline this guarantees you a spot in the tournament. Often times there are too many owners, or too many riders. When this happens they can pull you out of the tournament if you are not linked with a rider/owner to make an even field.
I have also been in tournaments where there were too many owners, so the tournament director paired boaters up with boaters. This is something that often causes huge problems and fights.
With FLW on their application page there is a spot for you to put your guaranteed rider/owners membership number in to hold your spot. This doesn't mean you will be fishing with that individual.
I got paired boater boater last year and want to try by all means not to let that happen again.