“Why would he take the job knowing he would have to recuse?”
Because... the recusal provides political cover for Huber... who is investigating DOJ/FBI abuses.
Mar 2, 2017 Sessions recuses without briefing P0TUS.
Mar 29, 2018 Sessions appoints Huber to look into FISA abuses.
Why did Sessions bring in Huber at such a late date?
Because of this right here (one month before):
We like Jeff, he's a good man. Let's not get carried away with inventing a fiction to cover his rear. He was not a good AG.