[Arkcon]

Well, assuming you haven't given the AI a bonus when you set up the game, there are a couple of reasons why they can build more units faster than you can.

If their production rate is higher in their culture setting, or racial characteristics, or hearty industrialists racial trait they'll always have a few more satelites per turn.

As long as it has the income it will build units, it never stops, unlike me for example, who waits for two component techs to advance before I jump into production.

I'm playing against the United Flora, they put 100 satelites, on a dead end warp point, leading to a neutral. Bottom line, the AI wins the units rating, but so what.