User blog comment:DarkJester4114/Another Interesting Idea by DarkJester4114/@comment-116.14.223.48-20140812155710/@comment-25037570-20140812175416

I mean you can only have 2 Double types in a team, meaning you can have the 3 unit slots be filled by any unit other than double types, and the friend slot. You's still have 5-6 units out on missions, but no more than 2 are Double types. I may have to specify that if more people are confused like you, but thanks for pointing that out!