Bumping this one back up.
Protection used to be a variable between 3 and 20 hours.
3 hours if you left less than 20% of your army home. This puts a barrier up for castle passing. Con is that late game I think it gives a huge advantage to races that normally get Gate. It does also introduce a scenario where people use a tactic to intentionally fail attacks to get the at home army below 20% then break them. Nothing like watching the vultures slowly pick at your kingdom every 3 hours just for your army to get home and disband because you have no GH.
On the other side of the coin, max prot gives people adequate time to rebuild. I think any castle being lost should result in max protection. Current state of 15 hours is too low. Non-gate users can always be hit twice before their army returns.
And who doesn’t love a good land hit that gave some random ass amount of time as protection?