I am sure that kind of micromanagement will not be accepted. So we have 2 option.
1-Allowing clan parties to take men from garrison like how it is now (text can be added when they take)
2-Disabling this feature so clan parties will not take men from garrison (we can make this only for player clan, other clans work as they work now)
Hey mexxico,
The first thing I always do when visiting the forum is checking everything you post because it's interesting and I learn something about the game's mechanics from it. I can't wrap my head around this post though. I see this type of assumptions almost daily in my work, and while I don't know TW's inner working and you do, I do feel this will not lead to the "right" solution.
In this instance: what's keeping you from offering 3 options? The third, the preferred, being: 3-Pick allow all/allow clan/disallow (or something like that). Even if that does gets put down - at least it's been on the table and the "right" solution as least had it's time to be considered.
Assuming it just won't be accepted (even if you're probably right) should not be a reason to not offer a solution you yourself (backed by community members) prefer.
I'll get off my high horse and crawl back into my ivory tower now.

Keep it up, you're doing great!