Yes, without a moment's hesitation. You hire the significantly better coach 100% of the time.
There's zero good reason to take a chance on a "wait-and-see" guy if you have a home run hire lined up.
I don't necessarily agree with the premise that if he is interested he's only interested for one year. It's much more likely he wouldn't be interested at all.
Even if he is only here a year, that means he did a really good job and someone poached him.