I agree with this idea
Maybe do some changes like make the player who jumped ship unable to attack players in his old kingdom until a specific amount of time.
This game definitely need more tribes, as a asian player I felt quite alienated when I played my first round of travian.
This game is based on real historic races so it does attract players who are interested in this and it's part of the fun of this game, but Asian's won't get this fun because there are no races they are familiar to choose from, I hope I can see the Hun and japanese someday.
At last, I believe the devs made TK a independent game because they want to try something new, a new tribe would be the best to try than anything else.
The horn of Nature should be designed to help defensive players clear animals instead of boosting offensive players even more.