Heir works better with the Army build. For Dragons I'd actually probably go no Agenda unless I was running a fair amount of claim 2 plots.
I was talking with Damon and hes said that getting characters that are not alive during the books is extremely difficult, and generally frowned upon. I doubt we'll see any more dragons until Melisandre raises one or we at least get whispered rumors of more in the East.
I would like to see at least one more attachment that gives the dragon trait and some utility characters that get stronger when you have a dragon in play on the order of Qartheen Fanatic, The Good Masters, or Slave Masters.