I think Klopp has a case. What Pep has done in the league has been amazing, but he could essentially buy whoever he wanted over the last couple of years, and when it really mattered he lost the head-to-head with Klopp. The Coutinho transfer distorts the finances somewhat, but Klopp has still managed to build his team without spending ludicrous money. I do think it's between those four, and in the direct comparisons I have Dyche slightly ahead of Rafa in the "working with what you've got" stakes and Klopp slightly ahead of Pep in the "FM 2018" stakes.
Think it's just based on Premier League. I'd definitely give it to Guardiola this season