Production, yes; storage, not at all. A realm could have massive production, yet constantly sell the food; another realm could have a very small surplus, but horde it forever and buy food from their neighbors and have a massive stockpile. Aurvandil, Morek, and Iashalur all have stockpiles, but there's no way for my character can find that out.
Oh hey ruler person, lets publish our stored food information so all those starving realms can EASILY see which realm to go to war with to alleviate their problems. There are PLENTY of ways for our characters to find out this info, but it takes time. When Arcaea was arguing that the Dark Isle had broken their treaty obligation to sell surplus food, the damn northern barbarians claimed they had none, so you know what we sent infiltrators and traders to go peak into their warehouses to find out the truth.
