What surprises me is when high ups in the Lurian Kingdoms cannot put two and two together and use their keen sense of deduction to realize that the realms of Barca, D'hara and Terran are federated and as such they are simply another power-bloc that is based on cultural and geographical similarities, much like the Lurias (and much like SA). They don't even have to know that the alliance is referred to as the Veinsormoot to understand the fundamental nature of the alliance.
What surprises me is that you think that knowing that Barca D'Hara and Terran are a federated Power Block instantly reveals the purpose of the Moot. We know of the relations between the three realms, we don't necessarily know what the Moot is for.
To be fair, there is very little interaction going on between the 'Moot and the Lurias on a player to player basis (as far as I know). I have noticed a lot of Lurian players that complain that the 'Moot is secretive, or, more accurately, that we do not advertise our purpose. I think this is a hypocritical position to take since the only reason players of the 'Moot have any semblance of a notion as to what the Lurian "alliance" (or whatever you would call it) is, comes from the fact that all those realms were friendly colonies of PeL. Thus, with a little intuition, a 'Moot player can look at the Lurian kingdoms (i.e. PeL, LN and Solaria), look at their diplomatic relations with each other and safely conclude that this is a bloc of cooperative nations. Our understanding of the Lurias does not extend any further than that.
Like has been said numerious times, IC we don't care that much if we know about the moot. We do get tired of the attitude that some have in these forums that we should be taking the Moot seriously, or somehow know IC how the Moot relates to the federation. Of course we as the players know what the Moot is for, but our characters may have much less knowledge. We don't run around expecting other nations to know anything about the Halls of Luria for example.
I understand that the name Veinsormoot (which is gibberish if I understand correctly) can be confusing at first, however, there is a very clear and well organized wiki page describing the nature and mandate of the 'Moot. The Wiki is IC knowledge, much like a library, and to think that a Duke in the Lurias or even a Lord, would be so caught up in their own affairs that they would refuse to take the initiative and learn at least the mere basics of their neighbors, and potential rivals, is very, very un-SMA.
The wiki can be considered IG knowledge, but it is unreasonable to expect every character to have read every available "book" from the wiki. Luria does have a Royal Archivist, I'm sure when she has had the time to review documents about the Moot and have them added to our libraries we will all be better informed.
Besides it is quite in keeping with SMA to underestimate your opponents and just assume that your forces are naturally superior. History hardly suggests that all high ranking nobles bothered to learn anything of real merit about the opposing forces, beyond basic military intelligence.
