This is a great thread and actually hits up on a lot of the issues I have also experienced and things that I already have intended to modify and change!

Originally the idea of this mod was to complement the base racial and army units and mix it all up but as the mod grew and evolved it became clear very quickly that the sheer amount of new units and especially a lot of them being unique kind of overtake a lot of the racial and class lower tier units. With that in mind I had moved forward to develop a system to make building nothing but them viable (but at the same time (with lots of balancing) not too overpowered to the point where going classic is no longer viable). I'll lay out what I have planned out real quick!

I am scrapping the idea of ONLY being able to build t1 units and having them evolve (however that is an option, and it will be more viable if you build your city in that direciton).

I am making a very vast guild structure tree where you actually (for all gaming purposes) build your own guild hall that you can customize your own style of adventurer, to explain:

Building the City Of Adventurers (The Biggest Version of the Adventurers Guild Hall) does cost a bit of money initially, but grants you access to these templates:

-4 "Small" Room Templates non stackable Building
-5 "Small" room templates stackable Building
-4 Medium Room templates Building
-2 Large Room Templates Building
-1 Hall of heroes Template building

At First this doesn't sound like a lot of customizing but what's built into these buildings are a fairly large range of selections for EACH building template. Example:

The 4 Non Stackable Small room buildings you have access to 10 or 11 different types of rooms that each give different bonuses. Some give movement speed in own domain, some grant adventurer units extra medals, some grant special unique abilites like Reaction instincts and others are more utility like gold and casting points. This is a very basic example as each template grows in size so do the uniqueness of the bonuses. Without Spoiling too much it's possible to completely modify how the meta would work in AoW simply by building your buildings to specialize your units towards a specific direction.

Hall of heroes takes this a step further and redefines (without breaking or making untis overpowered) how to play the game. For Example:

Age Of Piratism - This is built by outfitting a Hall of heroes and grants over 15 different status effects and abilities to make your units hate fighting on land but love fighting in the water, with special abilities designed to make them feel like pirate units.

As you reach larger template sizes you can build buildings to build higher Tier units as well, but the drawback is if you purchase these buildings you lose out on room slots needed to modify and strengthen your army, So you have to make the choice between building a specialized army and having access to your strongest unit to build.

Due to this however I think unless popular demand says otherwise I will keep the requisites for the adventurers seperate (aka not being able to use dungeons and other tiles) to keep the base units viable and still unique in their own way. (Don't worry, the buildings you'll have access to build will more than make up for this I truly believe)

This isn't a far off future concept for development either. I am 90% done with all of this, I should have this up and done by the end of the week. Hopefully you stick with the mod and let me know how it feels once it goes live!

Very interesting. I look forward to seeing what you are putting together.

Thanks again for your efferts.