I guess you can't say Man City are in poor form... It's just that other clubs are playing better this season... That's why the EPL has a high competition in the standings... It's not easy for Man City to play in the Champions League and in the EPL... But I think that in the second half of the season they will be able to get to the first place, as it was last season...
Manchester City still has the possibility to return to the top of the standings if other teams are not consistent enough in the second half of this season. Because Aston Villa and Liverpool are still showing quite impressive performances this season and are also likely to continue again in the second half of this season. And this will certainly prevent Manchester City from reaching the top more easily because the level of competition this season is much different from last season.