It may be possible, but we could not find an implementation that would not hurt new honest small players.
Imagine a new player moves to a kingdom without a good king, and, what is worst, one that just wants to take advantage of the governors...
Now think about that new player, that doesn't know much about Kingdoms and has the same issue in 3, 4, or 5 kingdoms... and let's say we put the limit in 3... we are leaving that player stranded in a bad kingdom, and, the most probably end would be that the player eventually leaves the game world and who knows if the game.
It is programmatically impossible to differentiate that scenario from someone that is taking advantage of the feature.
So for now, the best way to combat abusing the feature is reporting the players using it though help.
But we are open to other ideas to see if we can improve the situation somehow that we didn't find yet.
I'm sorry, but if you want to keep a beginner, implement Travian Plus directly in the game for everyone. The absence of menhir limitation has, in my opinion, nothing to do with keeping new people on a server, it's frankly quite the opposite. I'm not sure the new players, as the old ones, can enjoy taking 4k clubs from a bunch of cheaters and see the game administration do nothing against it.
Moreover, in this game there are bad (bad, not cheaters) kings, dukes and governors. You can't protect the other players, and a fortiori the beginners, from them. They are part of TK, like they are part of every game.
If your point is to protect beginners and keep them on this game, there is planty improvment to do, and I have seen a lot of proposals in this way made by the players for years.