If you follow the Premier League games you understand in this league that's pretty much normal to see a team bring in the first place in the league even until the last weeks of the season but in the end, the other team wins the league and that does not surprising in the premier league because there is a hard race between all the teams.
I think even after the good performance we saw from Arsenal in the first week of the season and the weak performance we saw from this team in the last games, it doesn't still mean to say they are the only team got more chance for the title and I think still teams like Manchester City can have chance to take their place.
Yeah you're right, this season is different from previous seasons there are at least 4-5 teams that take their place at the top of the standings but not for long time this means that no team is truly consistent and there are always obstacles, currently Liverpool are at the top of the standings but in the next few weeks their mainstay players will be absent because they play with their country. On the other hand, Manchester City seems more prepared with its main squad and we can see improvement in this team.