It's not trivially explaining anything though is it.
They'd been speaking to a world class manager to come in for months, who would have been anyones first choice if they had needed a manager at the time.
He was literally the biggest fish available at that time, and they got him.
Lets lay out the groundwork.
You said 3 teams, including Liverpool, did not need a manager.
I merely pointed out that, yes, they actually did need a manger.
Congrats on the fluff surrounding the appointment, but as the incumbent had been dismissed, they needed a manager. It's as simple as that. You can go on and argue all you like, but it doesn't change the fact that they needed another manager.