What's in a Theme -- Thought for Dom3

[rylen]

First, to state the obvious...

I can easily divide existing themes into two type:
Unit themes like Ulm Iron Woods and Abyssia Blood of Humans. These change the units available for play, generally removing and substituting.
Effect Themes like Desert Sun and Golem Cult. These are less tangible.

In Dom2 you cannot take more then one theme. Of course, you cannot take more then one unit theme. But, should you be able to combine a unit theme with an effect theme, or take multiple effect themes?

I see a few reasons no.
--Programing. Current modding treats both the same. If the design team uses the same engine, Dom2 has serious obstacles to patching in that as a change. Since Dom3 will inherit from Dom2, this limit may stay. There's also the matter of checking that the conditions for both themes continue to be met.
--Game ballance. You can predict the power of a single theme. As more get added, it could be harder to ballance. I think this would be ironed out by the community over the first few weeks.
--What else?

So, why do it? Mostly I think this would allow unit themes to behave like normal nations, and that that's good.

So, what do ya'll think? Is this interesting? If so, is it ballanced? And should it be part of the wishlist?

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An unrelated meditation on theme in the "cool idea?" Category.

Magic path unlocked themes. Pretenders w/ a minimum number of paths in certain magics get the option of picking up certain themes. This could be another incentive to take bad scales and get a 10Path. Plus other cool stuff. But it is more to keep track of.

Looking forward to the answers.

Rylen