All in all, this particular rule is nearly worthless, both in the way it is being interpreted, and in the way it has been enforced in the past. I can think of at least two secession cases on EC that were ridiculously blatant circumvention of multiple game mechanics, including the recruiting mechanic, that were shrugged off as OK because there was some RP behind it.
Well that's really been my whole point here. However, it now seems to me that circumvention of game mechanics isn't really what the rule is designed to prevent. Insofar as that is the case, it still serves a purpose, which is to ensure that people don't nakedly use secession as a way to power-game without at least coming up with a reasonable story justification. The rule seems to be more about preserving atmosphere than actually preventing the circumvention of game mechanics, for which you have correctly pointed out that it is nearly worthless.
Edit: I will also note that I think that the rule is pointless either way, and poorly written to boot.
