Board Game Arena

I would really be interested in understanding why this tie breaker has been chosen by the designer?

I've the feeling that this is the worse idea he could have. Stars create such random games, and as if it was not enough, in case of a tie, the player who got more luck during the game with stars, gets a last advantage with the tie breaker.

It should clearly be the opposite solution.
Is there something I'm missing?

I fully agree with you -- I think fewest stars should be the tie-breaker. The game should (IMO) be designed so that it's mostly about getting the cards in order, matching colors, etc etc, with stars being a small extra add-on. And, if you've tied with somebody who has more stars it must be because you did a better job with the card ordering, and you should win the tie-breaker.

Instead, stars end up dominating unless one player is massively better at the ordering aspect. And the tie-breaker emphasizes that.

I don't think you're really missing anything; I think it's the designer who was missing something. The simple truth is, sometimes games aren't well-designed. There's not a lot you can do about that.