Why can't I hire more Metsuke in Shogun 2 Total War?
Asked 2 weeks ago and if no-one has further information will accept this as the answer:
From browsing forums it seem there is a hard-limit of 5 agents of any type, regardless of how many chains you have. You can never have more than 5 Metsuke, 5 Ninjas, 5 Monks, etc. http://forums.totalwar.org/vb/showthread.php?134068-Where-to-build-markets-only-in-fertile-lands/page2