I agree with the above. Maybe it's too difficult to enforce that particular rule. So why not tweak the mechanics of Path to Pandora slightly.
1. Capital can only be of the starting tribe
2. Don't allow tribe specific buildings to be built in in any village that is not of the original starting tribe.
Of course that might just lead to a 100% Egyptian start for everyone, but at least it's not taking advantage of a rule that can't be enforced.
I agree with these as viable options, though you're right many more people would just start as Egyptian. And (not that it matters) but my opinion on rule 1.1 is that if an account is built solely for the benefit of another it is illegal. Therefore, creating an account just to build an Egyptian cap for another, then deleting is violating the rules. Pushing an alliance-mate would not unless that's all the account ever does. However, the rule is impossible to enforce without mind-reading, so it doesn't matter anyway.