Did you forgot about the new engine? Its not just a handful staff that is working on a new brand game, and new Engine. That is not small number of employees.
Lets see the time line here.
On October 7, 2015, Battle cry studio (Known as Bethesda studio Austin, SA) halted the development on
BattleCry game, to work on different projects.
On November 2015, fallout 4 was released.
SA helped the modification and restructuring of Bethesda's
Creation Engine after Battle cry was halted. They worked with Maryland on fallout 76 MP, along side ID.
Maryland started CE2, and Starfield early production along side it. With SA helping them with f076, they had their full eyes on starfield and creation engine 2.
in 2016, SA replaced
Certain Affinity on assisting
id Software with development of post-release multiplayer content for doom.
in 2017, Rich Vogel the president of Bethesda Studio Austin (SA) left the company, to join certain affinity, who worked on doom MP.
June 2018, Starfield had a teaser trailer for their game. During that time, the game was in playable state.
November 2018, fallout 76 was released.
2018, Battlecry studio got renamed to Bethesda studio Austin. (Which is why there is no record of bethesda Austin).
Post 2018, Maryland studio went full production on starfield.
That is the time line we know.
en.wikipedia.org
We'll walk you through everything from your first character creation selections to your eventual journey into New Game+.
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