Michael Keane is the same as James Tarkowski or Ben Mee, a player who can do well when asked to consistently head balls away from his box but none of them have a positional understanding fit to make them a top class CB. He has some good attributes but every player at PL level does. He is not fit to elevate a team on his own and he should not be close to being a first choice starter CB in a team wanting to win things.
Keane, Tarkowski and Mee can do a job in a good team as a second centre back alongside a real leader but any less and you get what we have, mixed performances.