IMO Keita's best match for Liverpool.
No, Liverpool's midfielders are not that great. Their top 3-4-5-6 are not more talented than Barca's and any of them would be hard pressed to start of Arthur-Rakitic-Busi. Now they may have a better sense of their job, and they are deep.
Best midfield IMO are City, maybe Madrid clubs too.
Liverpool and Barca have the best attacking trios however (Liverpool b/c all 3 are outstanding all around players; we belong simply because of Messi but Suarez/Dembele/Coutinho are pretty good).
Liverpool also has the best defense (combination of back 4 and goalie). However Messi magic can break the best defenses so we will see.