one set of studios puts out Spider Man, Horizon, Bloodborne, Uncharted, Last of Us, God of War, etc. The other is putting out sea of thieves, crackdown 3, state of decay, Halo, Gears, etc.
It's not a numbers game, it's the quality difference between the studios.
Having said that, can't wait for wasteland 3 :)
Quality is a debatable topic, The games you picked above is more a preference thing. All those games are completely different to each other so apples to oranges. But if you want to compare quality than its best you put simular games togother. Better comparing same genre games like Halo 5 up with games like Killzone SF or Grand Turismo Sport up against Forza Motorsport 7 etc.
MS claimed most of there studios have 2 teams working on games, eg Rare is making Everwild while the other team focuses on Sea of Thieves etc.