Since I'm dumb and did not find this thread while creating my own, I will post numbers I found here, because they are different then OP's.
Few caveats:
1. Japanese studios don’t have a huge presence on LinkedIn, hence low number of Tango Gameworks employees.
2. I’m not counting publisher arms like whole Bethesda Softworks. Just individual studios.
3. Yes, I know that numbers are not exact, but it’s certainly better than nothing, right?
4. I also collected number of employees in June 2021 so I will put it in bracket so you can see how big of growth (or otherwise) every studio experienced in year and few months later.
Mojang Studios - 925 (674)
343 Industries - 527 (564)
ZeniMax Online - 521 (457)
Bethesda Game Studios - 441 (390)
Playground Games - 381 (314)
id Software - 304 (286)
Rare - 286 (267)
Obsidian Entertainment - 282 (237)
Arkane - 270 (257)
Turn 10 - 200 (163)
The Coalition - 191 (196)
MachineGames - 158 (130)
Xbox Game Studios Publishing - 148 (83)
Ninja Theory - 136 (122)
Undead Labs - 129 (94)
inXile - 116 (110)
Compulsion Games - 91 (70)
Double Fine - 78 (79)
The Initiative - 49 (72)
Alpha Dog - 23 (16)
World's Edge - 12
Tango Gameworks - 11 (9)
Roundhouse does not have presence on LinkedIn, but I individually counted around 60 employees.
And just for fun, there is also number of employees from ABK in case deal goes through
Infinity Ward - 635
Treyarch - 595
Sledgehammer Games - 532
Beenox - 493
Raven Software - 382
Demonware - 259
High Moon Studios - 246
Toys for Bob - 142
Blizzard - 5754
Proletariat (part of Blizzard) - 37