I think placing mules around would clutter the landscape and add to the server lag. That is essentially what a "fleet run trading post" would be. If every fleet had one, well....no point in having an exchange anymore.
Also, this is STO, not Final Fantasy. Nevermind the WoW references in the OP--there's too much FF in it for my blood.
But I do like the idea of tailoring as a specialty, WoW as it may be.