When you word it as "Jedi mind tricks" I'd have to say no lol.
But I do think it falls somewhere much closer to the middle than you are saying.
A good GM gets good deals. There are "how the hell did you get that for him?" deals every season.
I'll give an example of what I mean from a previous sales job. The boss man loved to say "This is a sales job. Not a customer service job. If you only make deals with people that do all the work for you, you aren't doing your job".
Does Landry need to Jedi mind trick the Lakers to be a good GM? No. But if he goes every offseason just saying "Argh, nobody wants to give me anything close to reasonable", well, hes not doing his job. He needs to find and negotiate good deals. That is his job.