We've already got a variable perk system based on how many players are on for each country. How about the system is expanded to award reset perks the same way?
Right now, you get 70 perks (I think) in each catagory if your country wins the war.. a change
If your country has the same number of players as the country that lost the war, you get 100 perks. Then, that number can be reduced by the same percentage of numerical advantage the winning country has over the loosing country.
Example 1. Rooks have 100 players and knights have 100. Rooks win the war and get 100 perks
Example 2. Bish have 200 players and Rooks have 60. Bish win the war and get 30 perks (Rooks have only 30% players of Bish)
To prevent the loosing country from simply logging off, give them the same percentage of the perks the winning country did not get. In example 1, there is no number difference, so the loosing country gets 0 perks. In example 2, the loosing country gets 9 perks [ (100{max perks allowed} - 70{perks not earned by winning country}) * 0.3{percentage of players}