Ram that submarine

In my quest to find more ways to nerf players relative to AIs in civ 6 I have come upon an old solution:  Remove upgrading.  In baseline Civ 6 you can upgrade units by paying gold, turning a warrior into a swordsman, a swordsman into a musket, etc.  The AI understands this, and it does upgrade its units.  Unfortunately it doesn't understand the policy that reduces upgrade costs by 50%, so players get a massive discount on upgrades and the AI doesn't.  Players also upgrade units that they have carefully levelled up, so they get powerful, fresh, high level units when a new tech unlocks.

So what happens if I just remove upgrading from the game?  When you unlock swordsmen you can't just upgrade a ton of warriors and have a terrifying army - you have to build those new swordsmen.  I tried this in my Civ 5 mod and it failed because unit maintenance scaled with time, not unit type.  The AI kept around those low tech units forever and paid enormous sums of gold to maintain them.  It crushed them because their economy was strained paying for a worthless military.  In Civ 6 though that isn't a problem - those club wielding warriors that are left sitting around aren't much use but they don't cost much either.

This change really stopped me from building up an invincible army.  I managed to promote my units but eventually just disbanded them anyway - that slinger may have 4 promotions, but it will die instantly to an attack from a musket, so no point having it around.  I liked that change, and I liked that I actually had to build new units when they showed up.  It felt better.

There were some silly results though.  At one point I declared war against an AI on another continent and sent my submarines and battleships sailing across the ocean to attack.  I got a massive slew of combat notifications and realized that a fleet of galleys had attacked my submarine.  I don't know what wooden ships sailed by people with clubs thought they were going to accomplish, or how they saw my submarine, but a half dozen of them attacked my submarine in a single turn and all of them sank.  They did some damage to the submarine, so I guess one of them managed to ram it or something....?  When my ground army finally arrived after the naval 'battle' was over, the enemy ran in with a combination of anti tank units, infantry, and horsemen.  Not proper cavalry, no, these were people on horses who didn't even have stirrups or steel weapons.  Unsurprisingly, those horsemen did not contribute much.

I think this sort of thing confuses the AI.  It calculates army strength by adding all combat strengths together, but that isn't a useful metric.  Even if the AI has dozens of galleys and a much bigger total my submarine will sink all of them effortlessly.  Plus war weariness is based on how many units die, so in a modern war the citizens get sad when horsemen die just as much as when tank units die, even if the horsemen are irrelevant to the military outcome.

If I could train the AI to disband outdated units this would be a good solution.  It would allow the AI to maintain better troop parity and prevent invincible high level player armies and silly timing pushes with crossbows and such.  Unfortunately I can't train the AI to disband units (if you screw up teaching the AI to disband stuff the consequences are a disaster, so it is no surprise that it doesn't even attempt to do that) so this isn't an option.  If I want to reduce the strength of player armies I need to go with my earlier solution of reducing experience income or I need to accept that the AI will have swarms of trash units around everywhere.  That is, until a nice, cleansing war comes about and all of their trash units get vapourized.