Well it's not that complicated, but it might look that way if you only look at the names of the games and the names of the developers/publishers.
Astragon's current simulator has nothing to do with Vstep.
Vstep initially made Ship Sim 2006 as Schiff Simulator 2006 as a German-only version, way back when, and they used Astragon as their German publisher back then.
When Vstep's game was deamed succesful enough to continue onwards with it, they expanded further and that became the ship simulator series that we now know.
But that has no ties with Astragon's own games, or other titles by other developers that they publish too. But they do offer Vstep's (later) games for sale too. And they might look slightly different if you only look at the box, but that's just regional differences, it's still Vstep's games.
Astragon recently just made their own simulator as well. They make tons of them, the weirdest stuff you can imagine has a simulator version on their website, it seems. Of course not all of their own making, but some are. From driving a garbage truck to cranes to forklifts, ambulances, buses, down to deep sea diving and angling/fishing and such stuff. I haven't checked in a while, but I reckon they'll have 'walk the dog simulator' and 'mow the lawn simulator' and 'run down to the shop to get a carton of eggs simulator' and what not, by now too.
But yeah, Vstep and Astragon are two seperate entitites and their games are seperate too. Astragon just published Vstep's game(s) in germany.
I hope that clears it up. The confusion is logical though, if you browse through their website.
Regards,
Fred