I was noticing while playing Brawl with a buddy that we could not both choose Lawbringer. This brought about the thought of why the 4v4 game modes also do not block players from choosing multiple of the same hero. I understand that hindering the freedom of players in choosing the heroes they want to play is "not fun" and people will complain. Some heroes have high crowd control kits that make playing against it the absolute worst. My friends and I have even been guilty of playing "belly bros" by rolling 3-4 Shugokis in Skirmish and one person Demon Embraces a player while the other 3 charge unblockable heavies to one-shot most people. The intr5oduction of both Shinobi and Centurion has made this even worse somehow. It is annoying to get into a lobby of eight people, 3 of which are Shinobi and 4 are Centurion with usually me being the sole person playing not a new character. I have seen multiple montages on YouTube of four Centurions running around with the damaging punch and kick perk and getting someone in a corner and kicking them to death like a scene from American History X. By reducing the number of duplicate heroes on a team it will make players diversify in their hero selection and learn new warriors instead of taking advantage of what is currently overpowered and unfair. You can not defend yourself when one person is attacking from in front of you while another spam kicks from the side and a third guardbreaks from the other side. You can only defend against one of those without opening yourself to the second and third and in that interrupted window damage guaranteed damage lands and the players rotate role.
TLDR: Reduce the number of duplicate heroes allowed on a team to increase diversification of players and experiences.