This rule isn't really going to affect anything. I understand that the same members are spamming the same thing in 3 different threads, but honestly, this won't fix it. All this will do is 3 things:
A) Kill off 2 or 3 of the TCG Teams, because multiple members are in different teams. 2 or 3 are going to just die immediately, because they couldn't keep enough members to stay active.
B)Prevent new teams from being made. All the members will already be on 1 team, so there will be nobody left to join the new ones, thus preventing the creation of new teams.
C) Not fix any spam. People are spamming the same thing in 3 different threads, yes, but all this rule is going to do is nothing. The same topics will be spammed just the same in the same threads, but instead by different people in different threads, but the same exact thing is going to be discussed. This rule really isn't going to help that fact at all.