MS didn't disbanded studios like Ensemble - they made restructurisation disbanding studios but at the same time absorbing key development teams of those studios into 343 Industries and other studios. it's easier and cheaper to oversee small development teams in one place by one executive than having 10+ different studios each with few development teams, 10+ executives/producers overseeing their work, 10+ R&D teams to support them, MS supervising guys in each studio etc.
plus they don't have to maintain those studios when they don't develop any games unlike sony.
MS owns IPs and few bigger studios making their most important franchises and couple studios on second party deals - it's cheaper and without owning original developer of each IP they can still make a deal with him to make new entry in that IP just like Mechwarrior deal with FASA or whole point of making Feelplus studio by Microsoft(yeah it's independent development team but they still have to work for both mistwalker making 360 games and microsoft).







