Honestly I don't think Sony can afford that many companies, at least not in competition with MS:
MS: EA, Activision Blizzard (King included), Rockstar, Konami, Bethesda,Ubisoft.
Sony: Bandai Namco, SE, Koei Tecmo.
Nintendo: Sega (Atlus included ofc), Capcom, Platinum Games, Level 5 .
I'm gona say that WB doesn't count since they don't work only on Videogames and related Merch...