My suggestion is that if two alliances have mutual DEFEND orders, then
faction information should be revealed. So if I DEFEND faction [3xy]
and [3xy] DEFENDs me, then in my turn report I see something like:
> Seen here:
> John Thumb [333], with two peasants, ten sailors, faction [3xy]
Note that if you want to have a particular unit conceal its faction
identity, you can simply have that unit issue NEUTRAL toward the
faction you are hiding it from. So I don't think there's any loss of
sneakiness from the current system; it only makes it easy to cooperate
(which I think would be a good thing).
-- Scott T.