• Economic structures no longer collapse in a gentle breeze.
• Military structures, siege equipment, walls, gatehouses, and towers are durable. Sieges will take much more time and effort.
• 5x health for walls. Strong walls should now be the default for single-player crusader trails and learning campaigns. (Double health may not actually do anything extra now that wall health is 5x normal; will have to test it).
  

• Wood camps, apple farms, the barracks, armory, oxen carts, and marketplace are all FREE but anything free has a build limitation.
• Housing is much cheaper.
• More durable towers and walls mean they also require more stone; you might not be able to build a dream castle without taking it a bit at a time.
  

• Eastern mercenary troops are cheaper and crusader troops only cost weapons; slaves cost 1 gold and conscripts cost 1 wood. The idea is to make it easy to build huge armies for both players and AI.
• Troops have been rebalanced according to costs. No overpowered tanks and no fragile pincushions; every unit is durable. Arrows are no longer overpowered.
• Certain troops have more dynamic strengths and weaknesses; some succumb easier to pikes/spears, others fall to swords, and others to projectiles. Some units are extremely weak to diseases such as slaves and conscripts.
• The idea is if everything takes some time to kill, you will have time to focus on tactics and micromanage units a bit more without them dying too quickly.
• Siege units are durable in logical conjunction with stronger structures. Sieges will take longer, thus siege weapons will also take longer to destroy. Although structures are much stronger, I've made sure most units will not be able to damage structures.
  

• Everything except weapons will be bought and sold at the same price. Weapons sale for 3 gold lower than the buy value. This makes the exchange of goods easy to manage with a free marketplace. You should be able to set up an economy relatively quickly and not have to micromanage it so that you can focus on military tactics. 
• It is easier to manage your economy with access to fewer resources. Even if you have no natural resources, you can manage the purchase of hops, wheat, wood automatically in the marketplace to make ale, bread, and weapons for profit.
  

Author's Thoughts

All in all my results with people allied against computer players is that you can slowly manage your sieges and economy. The need to play strategically should still be important while not being so unforgiving. You can substitute troops easier since they all are moderately durable. You can go between a siege and the economy without losing your entire army within seconds. 

Be sure to provide feedback if you use this mod.

1.1.0 One major update pushed through and a minor one. The assets.v file did have an LUA script file for strong walls in multiplayer. I changed the default to strong walls enabled and made the health 5x normal. Walls also cost 2x the stone. Now single-player will see the same changes.

1.2.0 Second Update:
-Just recently started playing again and I realized I nerfed ballistae by way too much. Now the tower ballista and the fire ballista should both wipe out a slave or conscript in one shot.
-Artillery like Trebuchets were just too slow and inaccurate with stronger siege equipment to be any better than a catapult or war wolf catapult. I had to make catapults more expensive, do less damage and make them weaker to melee attacks, while still being resistant to arrows. Trebuchets are now more durable and do a lot more damage; many units are more vulnerable to diseases now too.
-Knight's horses went down too quickly because they don't use the armor values given to them so I just increased horse health by 6x what it was.
-I made arrows about 1/7th stronger because they seemed slightly too nerfed. Slaves and conscripts are twice as vulnerable to arrows than I originally had them. The problem was that ranged units weren't much good on the open field when they were too easily approached by weaklings like slaves and conscripts.

1.2.1 3rd, but minor Update:
-Increased the troop limit to 40,000 per map. With 8 players, that's 5000 per player.
-Increased the building limit to 4000 per map. With 8 players, that's 500 per player (if you have space on your estate).
--This allows for massive armies. Hardware and engine limitations will cause issues above a certain number of troops. For me, it was when there were more than 1200 troops.