He was probably a perfectly normal guy, but I doubt that he checked her out to "ensure compatibility." It is perfectly normal for young men to pretend that they are interested in things which they aren't in order to attract a girl's attention. Maybe some of the guys who approached her were genuinely interested in horses, but the majority probably just wanted to give a good impression.

There's nothing wrong with trying to give someone a good impression, but when you research someone's hobbies so you can feign interest in them, you are starting your relationship off on the wrong foot. If you can't be yourself around someone, then things probably aren't going to work out anyways.