Finish the season and evaluate him. This is now his squad, no more Emerson Royals. Eric Diers. Pierre Hojbjergs to fall back on when injuries or suspensions hit.
4 games in is a pointless metric league wise. Theres plenty of instances of teams starting slow and ending strong. And right now by right of not playing in anything, we're still in all the cups
The Europa League format runs through until February, so even by then we are still likely to be competing in Europe.
Absolutely no one worth a name is going to come in and "save us" if we get rid of him now anyway. Because all we'd have done is shown every coach in world football that we're happy to start building for someone, only to sack them during a bump along the way.