I would just...do this. Write a list of the awesome and exceptional things he imagines this company having. Ready?
Exceptionally metahuman friendly or extremely magically active for extra security or aligned with a weirdly stereotypical band of dwarves for extra security or extremely cyborg heavy for extra security or equipped with special electronics that are difficult to attack from outside the facility or combat trained personnel (with a penchant for swordplay) or all getting along despite what should be poisonous corporate/family greed.
And then? I'd tell him to, like, pick two or maybe three. That'll give it a stronger theme, a more realistic feeling, and make them less all-over-the-place and just generally impossibly awesome.
Maybe they're a badass security company called Gladius Enterprises, and they've got a disproportionate number of heavily cybered guards, and make a big point of branding their company with archaic weaponry, so every employee gets swordplay lessons at the annual company retreats, with fitness/fencing offered. So you've got lots of employees swaggering around the office with (ornamental, but functional) swords on their hips, and manager-types might even have monoswords and stuff...but the real power lies in the cybernetically augmented security force (also with a penchant for melee), because the company specializes in combat augs.
Or maybe they were initially backed, when the company was founded, by two families, not one. One is the PCs family, of course, but the other was the father of a dwarven family, many of whom suffered from sunlight allergies (as was often the case in earlier editions, when all metahumans had to have allergies), so they just embraced the stereotype and chose to live underground. Now the company's got extensive underground facilities beneath their main office, with production running day and night, nonstop, 24/7 (granting them a productivity bonus compared to their primary competitors, and a practical security boost, as well), and the friendliness between the two families has kept them all getting along well. Everyone in upper management is sincerely on board with their sense of community, and family members are concerned with doing their job first and foremost, not looking like they're doing their job by backstabbing each other.
Or maybe the company's founder -- dear old dad -- was remarkably open minded. In the first decades following the return of magic and the waves of goblinization, etc, he was in mild awe, not terror, of what was happening to the world around him. He was one of the earliest employers to offer incentives to magically active and metahuman employees, and many of those workers' children have stuck with the company (despite so many other corporations now doing the same)...even opening up the facility as a safe haven during the Night of Rage and other ugliness, decades ago, which cost him financially but built him a rabidly loyal core of dedicated metahumans and magicians, many of whom feel their families owe the business a great debt. Now they're way out of their "weight class," so to speak, when it comes to magical security, and have built a strong reputation and loyal client base thanks to their metahuman-friendly attitudes.
Or whatever. Like, pick two or maybe three strands of awesome he's wanting, weave them together, focus on them, and make them make sense. Make it clear to him that he should still be concerned first and foremost with playing his Shadowrunner (and not trying to turn the game into a corporation simulator video game or something), ask him how the unique traits of the company tie into his character -- did he learn combat magic or swordplay from corporate security? Does he maintain contacts with metahuman rights groups because of his upbringing? -- and...well...other than that, just explain to him that "his" company can't be super mega awesome special at everything at once, just like a player character can't cover all the bases.
Tell him you appreciate the time and effort he put into it, but that as conceived right now, it's a little over the top. Ask him to focus on a couple of things that really jump out at him as being awesome, and maybe sweeten the pot with a free contact or a bumped-up skill or something, if he impresses you with his revisions.
