Only 2 of Each Hero (Less Agents, Less Heroes!)
Limits both players and AI to only having 2 of each type of Hero or Agent. I didn’t see one that limited agents to 2, I only saw one that limited it to 1, so I made this myself quick. It took like 5 minutes and I’ve never modded TW before.
I recommend using something that increases the recruitment pool of heroes, to give you agency in getting the ones you want within this stricter hero limit.
Keep in mind that this means you’ll only be able to choose two magic lores when recruiting spell casting heroes! So choose the ones you want wisely.

I hate that the AI spams heroes and that you as a player are really rewarded for cramming many heroes into one army. An agent cap forces you to differentiate and possibly make more diverse armies, or to use hero types that are normally neglected.
It’s easy to find mods that make you overpowered, but hard to find ones that limit you. I think that games are best when you have to navigate limits, and this is where creativity can really shine.
If tides of AI agents still wander your map like they’re checking car door handles in a Walmart parking lot, consider combining this with a mod that forces the AI to embed heroes. This also helps the AI, since they won’t waste their hero slots with wandering vagrants.
This mod refers to the agent type keys. So If a mod adds a hero and is referring to an agent type that already exists, it should be compatible with this one. However, if a mod adds a brand new type of agent, then it won’t be affected.