Can a team play without MCs? Legal?

[Stars FC]

Yes you can. In fact my favorite formation currently looks like this.

------ST--------ST------
ALM-----------------ARM
----------------------MR
----------DMC-----------
DL----DC-DC-DC---------

Looks goofy as heck, but I've got good attacking guys on both flanks and use that strategy combined with really good strikers. I've been popping out goals like they are hot cakes, and the three DCs, and the DMC means I still have decent coverage in the middle. What I learned from experience you can't do is put three guys on either flank.