It seems that your Urchin is configured to measure hits on your server instead of page views (this is speculation since I do not have the link to your site). The high number could only be explained by the fact that one pageview would require multiple elements on your site (js files, css files, images, etc).
GA and Jetpack always have discrepancies and that is because the way GA measures pageviews v/s the way Jetpack measures pageviews. GA treats longer visits as multiple visits, a new visit means a new pageview (since you cannot have a visit without a pageview). So if you look at the pageviews, GA will always be more than Jetpack (I belive Jetpack pageviews are a hit on that page).
To summarize, yes the stats from different sources are different. They cannot be the same since their measurement is different. To avoid this confusion, start relying on one tool as your primary reporting tool, and have the others to augment your findings.
If I were you, I would use GA as a primary tool.