I don't think Manchester City is bad performance because last year they have bad start when primer league begin but they show how greatest performance when end league and success got the champion, to early to claimed Manchester City is not super power and they need time few match later to make them success on primer league again, many surprise will happen later to know who is the next champion again exactly when busy match because many team will loss most important player with injury.
That's right, this is not the result that can determine whether City are champions or not. It's not just City who have failed in early games at the opening of the new season. Many clubs are become champions at the end of the season even though it seems doubtful at the beginning of the season. Maybe, if in the first 10 games of the season City lost 5x, draw 5x, this is appropriate if City are considered to have poor performance.