It's all rather simple, you see. Jeff's pathology stems from his early career with the Griffins where the seeds were first planted. With the nurturing of his overbearing GM, and emotionally distant NHL HC, he soon flowered into full-blown psychosis. Jeff's GM was a narcissist who neglected his roster in favor of his head coach, Mike Babcock, whom he viewed as a reflection of himself. Young Jeff, sensing this familial dynamic, began play-acting as Babcock, the coach whom his GM lavished with the most attention and affection. As his GM encouraged this behavior, Jeff soon came to realize that through embracing this fantasy he could shift his GM's attention to himself. In this manner, his pathology deepened and broadened, encompassing a veritable stew of neuroses, prominent among them disorders of the histrionic and borderline personality variety, which, combined with the dissociation of his vivid, Holland-reinforced fantasy, blossomed into acute Autobabcockphilia, wherein merely imagining himself as Mike Babcock was insufficient to sustain the delusion.
His GM's own narcissism interacted with Jeff's burgeoning psychosis and the interpersonal dynamic gave rise to Folie a Deux, wherein the shared delusion brought to the forefront Holland's own lack of ability to build out a roster, manifesting in a case of Munchhausen by proxy in which Jeff himself is unconsciously complicit.
So as you can see, this all started with young Jeff's desire to live within Mike Babcock's... skin.