I am thinking of increasing the upkeep cost of many units, especially the higher tier ones.

How does it affect the AI? Does it create units rather and forget about upgrading the building with higher upkeep costs? Or can the AI adopt dinamically to the increased unit cost changes?

Another question would be that how is it possible to change the costs of upgrading units?

I want both the player and the AI to still recruit lower tier units even at late game for public order and defense purpose rather than only recruiting elite / high tier units.

I would even double or triple the upgrade costs of the units, because after the technological upgrade, at the current state it is not worth to recruit the worse tier of the units in 95% of the cases.

How can I edit unit upkeep costs and upgrade in the Pack File Manager?

Any detailed help would be appreciated

Best Regards