The main problem is the way AI lords behave on global map. They have nothing to do besides conquering. No feasts, no participating in tournaments, no solo patrolling their fiefs, no solo raiding, no nothing. A lot of this comes from deleting role of marshal and introducing create an army feature.
So my take on that. First of all, cost of gathering an army should be much more higher. Secondly, cost of containing lords in army should be a lot higher as well. Ideally army should disband after capturing 1 holding to give a breath for loser side. And at the same time higher cost of creating army gives time to lords to do their personal stuff (hiring new soldiers, patrolling, solo raiding etc) while they replenish influence to gather new army.
So my take on that. First of all, cost of gathering an army should be much more higher. Secondly, cost of containing lords in army should be a lot higher as well. Ideally army should disband after capturing 1 holding to give a breath for loser side. And at the same time higher cost of creating army gives time to lords to do their personal stuff (hiring new soldiers, patrolling, solo raiding etc) while they replenish influence to gather new army.