What makes you think you know better?
It was widley reported by more than one source that his agents were approached, and Tuchel was consulted, it even got as far as discussing transfers, and that is where it failed, Tuchel wasn't happy with United's transfer policy.
Now whether that was because he wouldn't have the greater say in purchases or not, or even the budget, isn't known.
It may have been an excuse on Tuchels part, he may already have been approached by the FA for the England job, I'm not a believer in coincidences, Tuchel turns down United, then only a couple of months later accepts the England job, any manager who has basically won it all in Europe would only turn down United for the chance to manage a national side.