I'm uncertain if this is WAY too late? But?

Can we have spells targeting the economy of the empire as a whole?

We have spells that target a city, but what about something that is dependent upon land development?

Currently, there is no land development. And even roads are pointless beyond running armies across your empire, and even then, its a bit easier to just cast flight on them or make a flying ship maybe?

But, how about the a spell that increases gold dependent upon the number of cities connected by roads to the capital?
Or a way to develop resources to increase their effectiveness? (and, guiding a bunch of "engineers" across the planes to do all that would be REALLY annoying, but allow it as an option at the beginning?) but a Global Spell that Develops one tile per city divide by (2 or 3) ( 1 tile per turn per city connected to capital by road? i donno). This would be powerful spell that could add a economic development side of the EMPIRE to the game that it kinda of lacks (MoM has always lacked this).

Spells to develop interconnectedness, roads, economics, etc.

For further development, maybe:
Allow ENGINEERS of a race to go to another races city and build / develop unique hybrids of certain buildings, and / or even buildings only available in a specific races city.
ie. Dwarven engineers should be able to go to an elf city and make their city walls Runic walls.
also, Dwarven engineers (maybe) could go to an elven city and build a building (of some kind) that creates special compound bows that add damage to all elven archers? Or even a special building that gives double shot to elven archers.

These things ENHANCE the uniqueness of each race, not unify all the races into a bland sameness.

Also, maybe to add to UNIQUEness, the starting race that a player gets also determines a SPECIAL building that a new race integrated into the players empire can build.
IE. Elves typically are all about range and archery type stuff, so an elven player who captures a high men city might be able to create a special building that enhances archery or creates a special High Men archery unit (an upgrade to the crossbowmen?)

Two possible options with this:
First option:
Have city reaction to this work be based upon racial interaction. So, some have neutral affect, or certain races even abuse other races in order to create a different kind of super unit, but it causes increased unrest in that city. (This kind of thing might occur between naturally inimical races (forest elf vs dark elf?) or maybe just is only done by "evil" races (orcs, dark elves, etc).
This means, new unit, or building or both? per race * number of races - 1 (so 5 races = 20 new buildings)

2nd option:
Overlord race can choose to create a lesser / weaker / different / (something?) unit that doesn't increase unrest so they two races continue to work well together.
Or Overlord race can choose to create uberunit by abusing slave race at cost of permanent unrest for all cities of that race until the building and units created that building are destroyed / freed / released / etc.
This one is worse than above, but gives CHOICE to player to be "good" or "bad" guy, first option takes that choice away / conflates that choice into race choice, but does take away choice to be "bad" high elves or "good" dark elves.
But: 2 buildings * races * (races - 1) (if my math is correct? ALOT of new buildings, sigh. ( so 5 races = 40 new buildings)