User blog comment:Miskos3/Fairy Tail Chapter 367: Jellal vs. Oracion Seis, Review/@comment-5268982-20140117180324/@comment-24066070-20140117195734

Bickslow controlled Elfman's body when fighting RustyRose and he "sold" his soul to Sayla, so she may be controlling his soul. We don't know if Macro target soul, body or both. But as you said, Bickslow is likely to injured to use his powers at full force.

I doubt Sayla would send Elfman into FT to cause a brawl, she would rather have him mislead them by giving false information, like sending them to the wrong places straight into traps laid out by Tartarus. Would also be nice be nice if she used Elfman to cause internal strife.