I have worked in the industry and this position is wrong. Most execs in the industry do both creative and business work. Harvey Weinstein, while not a director, was famously deeply involved in the creative of his films. Many directors have gone on to be head studios. Brian Robbins, the current CEO of Paramount, was a director for most of his career. Lucas himself is probably the best example here, actually running this exact company while also directing the prequels.
It is true that Filoni/Favreau certainly wouldn’t have the time to be as involved in the creative as they would if they were also the studio head, but the idea that they wouldn’t be involved in the creative at all, or that Kennedy isn’t, is the position that shows a misunderstanding of the job.