I had to check the ECL3 rules again because what you described seemed wrong. Let me clarify things,a dn keep in mind this is from ECL3 rules and may change in the very near future (altho it probably won't change that much).
So there is a difference between free agents and transferred players.
Free agents are guys who have not joined a team in the tournament yet. There is no limit to how many of these you can add.
Transferred players are guys who are on a team roster according to NHLGamer and are moving from a team to another. You can add up to 3 of these in a tournament. And guys can only transfer once.
Right now everyone is basically a free agent (except team captains) so feel free to add your 2 guys.