If the chances for win are accurate (from the Premier League on Google), which are as follows for each of the three:
Liverpool: 63%
Man City: 77%
Arsenal: 83%
Then it's actually more likely than not, that at least one of these three won't win their game (around 60% probability).
Of course, it's hard to put an accurate number on sports events, it's all just estimates mostly based on previous results.
Most likely to drop points would be Manchester City at the end of the weekend, this is because derby games are difficult to play and this is also Manchester United trying to find themselves Into the top four in the Premier League Competition. Right from when the season kicked off, I've always wanted Manchester City not to be Champions since I've also wanted a change, it's been three to four years and Manchester City has been dominating. They could still get all three points but it'll not come easy.
I think your right. Manchester City has more chances of dropping points. Luton Town and Manchester United are very strong challengers to Manchester City. More seriousness should be put into these matches because it will be part of what will determine if they win the league or not. Brentford have a strong and consistent defense line while Manchester United will do anything to win the match or attain a draw just like what Chelea did against Manchester City.