Kenchar,
I'm offended that you call nags mules. Hang on, it's calling the mules nags I don't like. (I think).

Seriously, about jockeys. There are good ones who might not have a high profile, or be regarded as "senior".

A good measure is to look at the jockey's average beaten margin over recent times - maybe the last 6 months, counting horses that ran say within 10 lengths (can't blame the jockey if the mule was a donkey). You can identify the jockeys that have skill and judgement without relying on their profile.