An excellent question.  I don't know.  Here are a few thoughts:

1) In Acts 13, the whole church certainly lays their hands on Barnabas and Saul to set them apart for the work of a missionary.  That's enough to make me think it's a really good idea to have the whole church vote to commission a missionary.  Is it enough to make me think it would be wrong for the elders to do the commissioning themselves?  Hmmm.....maybe.

2) One commenter mentioned Acts 15 in this vein of thought, too.  There's definitely a formal "deciding" and "choosing" there, done by the whole church.  But were Judas and Silas missionaries?  Or more like messengers from one church to another?  Regardless, I think this, too, would lend weight to the idea that in commissioning a missionary---one who is to represent the church and its beliefs---the congregation as a whole should make the decision.

I'm amending my list.

1.  Membership and Discipline
2.  Leadership
3.  Doctrine
4.  Commissioning of Missionaries
[5.  Budget]
[6.  Rules]

By the way, Wiki says that Henry Robert was a Union Army Major who, when called upon to moderate a Baptist church meeting, failed so spectacularly to keep order that he decided to write a book about it. 

So Robert's Rules came out of one man's frustration with an unruly Baptist business meeting.  Raise your hand if you're surprised by that.