Why should an alien culture have to act like humans? There's nothing wrong with the episode. Logical? Of course their choices are logical, you may not agree with the premises they work under but that doesn't make their choice unreasonable. Their species has a biological urge to mate which will bring on large numbers of rape murder binges if not dealt with. Further, they are a telepathic species which seems to play a function in this as well, whether as a cause or effect. Arranged marriages are a very reasonable way for such a folk to make sure the couples have someone to connect with and make sure outsiders tend not to break up. Breakups leading to someone dying one way or another. As a side note, I despise the way Trek fans throw around the word logical. Logical does not mean something will be peaceful, happy, compassionate, benign or in anyway nice. Logic is a system of reason. Any outcome can be logical, even fights to the death, it's just a matter of the premises you start with.