I think this would be great. It would solve a couple problems. Most notably, the "can you trust an adventurer in your realm from a player who has a character you are at war with".
Advies are supposed to be independent of the family, but there is always that OOC suspicion that they could be a double agent. If this were approved, then you would have reason and grounds to interrogate an advie from your own realm, ask him/her why they are poking around, torture them, gain intel, and send the lil bastard off to the gallows.
If this were approved, I think it would be worthwhile to make an advies scout report much more like a scouts, with units and numbers. An increase in risk should be partnered with an increase in reward. It would also make advie scouts MUCH more desired. I would personally love to see more employability of adventurers.
