User blog comment:Chancelot/Buddyfight Summer Bash Tournament!/@comment-24508385-20160208152840/@comment-25004901-20160208234600

He means JUST 1 simulator to use. Most prefer to use BFA, but some can only use Ota's. Having two different simulators for choice makes things difficult and causes  disagreements. It's best to have 1 set for the tournament to have as little disagreements as possible.