oh and @shiftrox I wanted to make a new suggestion, i'll have to think it thro
But its along the lines of kinda caping the invitation system, especially because the leaderboard, +3 points is big, yes for a new player.
But following the reasoning behind the multi accounting, you might need to apply the need for the new player to buy a tree or something like that.
If not it's a sink hole of new free to play players that only encourage hive farming and +3 leaderboard points (which again, is a big bonus).

The idea behind is like Splinterlands, not only you have to just invite people, but these people HAVE to buy the Spellbook.
That way they leave something to the game, just not only a new free to play player