Talk:Challenge Arena/@comment-86.183.8.195-20151023165845/@comment-26467509-20151023171712

It sort of mentions it. When you form your team look at the bottom right corner where it says "Brave Bonus". The lower that number (max is 2.50) the higher the chance the other team gets to attack first. I think if it's below 1 it'll even warn you that the other team has a greater chance of attacking first.