The ongoing embassy discussion gave me an idea of another external infrastructural element for the whole kingdom. Just as oasis can generate some extra resource, a wilderness tile could be made of use. While oasis affects your resource income, a wilderness crop tile would only affect your crop consumption.
That effect could be activated by letting each kingdom member send lets say 100 troops to feed there in the beginning. But that tile would have a limit of say 1k crop consumption in the first weeks of the game, so only 10 players could max out their troops...or 20 players send 50 troops or some cavalry and the limit is reached. Keep in mind that the
wilderness tile can only influence the consumption , while Oasis influences the production.
When players invest in that village, then the crop consumption limit could be upgraded and more troops could be fed there...maybe only king can upgrade it from the kingdom tributes tab, as paying from the tribute to build that collective crop tile. With each upgrade some % of the def bonus should rise too..works like building a wall there.
Ive always thought when people actively fill the oasises in the beginning, then they are safer for the greater amount of def there. This effect would also come into play with the new use of the wilderness tile and by working together, the kingdom could earn a collective bonus. As game progresses and the wilderness tile gets upgraded and civilized, the safer it gets.
By implementing this feature, the kings gain extra overlook of the contributors in the kingdom, the roles of the players and a peek at their troop balance.