Is there an accurate way to gauge the size of a potential enemy's total manpower without actually going to war and seeing his megastack smash you into pieces?
1 Answer
Possible duplicate of What's the difference between total, current and relative strength?, but since that's a slightly different question:
The 'Realm Tree' view on a character's page will give you a good summary of their total manpower, as well as the individual contributions of their vassals. It's the right-most icon in the top left of the character page, just to the left of their house crest.