The main difference between Theseus and OTL’s Ariane-1 is Theseus uses kerolox for the first two stages rather than UDMH/N2O4. Other details… wait and see! Well, you can say what you like about Griffin’s design choices, but his political engineering is first-class. He managed to make a government funded heavy lift rocket un-killable, despite the costs. The intent was “Sentry”, reflecting its military recon mission. I omitted to run this past my Russian friends for a sanity check, so “Chasovoy” is pure Google Translate. I’ll see if I can get a confirmation on that. As far as I know, there was no OTL programme with this name.