I should probably lay out why I think this could be a good addition.
It promotes the idea of active, experienced players going for higher point players - they will have more coins available, and so are more beneficial to noble from than smaller, less active players.
It gives new players a slightly longer run in the game. They can barb noble for a while, and because they are likely to just build 1 noble and slow-cap local barbs, they will never have a large number of coins-to-villages ratio, and so are less appealing targets (likely to be heavily defensive, and so lots of troop loss without the coin benefit when capping the villages).
It would speed up the gaming process when nobling out inactives in the later periods of the game. The sitter can keep minting coins as that does nothing to damage the account, and the people internalling can noble through the villages quicker as they get large numbers of coins from nobling the player out.
It slightly takes the emphasis off of continuous farming to keep top ranks; intelligent nobling would be more beneficial to top players (which is what I am doing on W52, and although I had a 3 month late start I am now nearly top 20, and last time I checked I was out-growing the top 20 bar rank 1 on a day-by-day average, as well as being fastest nobler on updating maps for some time).