So a bit off topic. But why not just make it so that peasants would start complaining more and more and more the longer you were at peace, and it would be harsher the bigger you were. So that small realms that cant attack anything wont lose everything they have, atleast not nearly as fast.
That was tried before. The issue, in a nutshell, was that the longer you were at peace, the hardest it would be to keep your realm together. This lead to increasing number of nobles being needed for courtier and diplomat work, loss of border regions and decreased taxes, reducing the army size.... and reducing the capability to wage war in the first place. Realms were stuck in endless spirals of peace.
