that should work, by putting the same score for all players it should not discriminate between them. However the idea of "random" is not really possible. I do not know how their formula works, but if everything is even it probably defaults to alphabetical order or something. What I suggest is do what you are doing but then play with the advanced options and change the unique player setting around, by default it is 1. Using one it would probably use the same two SG, PG, PF, SF, and change the center once each time, until you have used all of them then switch some other position etc... even with a pool of 35 people you are going to have more than the max 500 teams.
ps. why are you doing this? maybe if you explain we could try to help further...