tl;dr. We should be fine as long as we don't screw up in our own way.
Realistically, assuming we're heading to another 90+ points season, the only POTENTIAL threats would be United and Chelsea.
Arsenal shouldn't be a threat. Whilst they have a decent collection of high end talent and a new manager, their overall quality is just a bit lacking to carry them through. Even if they become more solid against the weaker sides I can't see them being ruthless enough to compensate for what will likely be points dropped in bigger games.
Chelsea are very difficult to predict. When they didn't have Europe to worry about, a fresh new tactic, no fitness issues and a highly motivated team they seemed to romp it. There's a chance they could repeat the act next season if they don't take the Europa league seriously. However there are also fears that there won't be the level of reinvestment as there has been previously, so whilst Chelsea might improve upon last season they might not match 2016-17 in terms of its heights. Another factor is who will their manager be next season. Conte has the capability to repeat 16-17, but he might match the previous season in terms of lacking motivation. Remember this is the guy who's won multiple league titles and once got 102 points with Juventus, so he's got a track record. If they brought in Sarri I can see them having growing pains like we did in Pep's first year, although they'd be one to watch the season after for sure.
Tottenham are Tottenham. We'll all probably have them down for 6th next season, and they'll finish in the top 4 anyway; they've developed a really consistent team. They might even run it close, but they lack that certain something to win it. They also have a serious lack of winning mentality compared to the other teams, which if at least one other team is up to task (ie us hopefully) it'll be enough to cost them.
Liverpool are a funny one. At their best you could maybe argue they're a match for anyone. But I could say that of us every season since 12-13 we didn't win the league. In fact you could make that argument for many teams over the years that didn't win the league. The point is, it's not really enough, in a league system anyway. I'll give them the benefit of the doubt for my analysis and assume they sign Fekir and a top class goalkeeper. They have it in them to be a 85 point a season team but that's their limit you'd think. The reasons they could be better have been stated universally by many on this thread and the media too. But their limitations are as follows:
- Their midfield: The biggest difference between this Liverpool side and Klopp's Dortmund. It's completely lacking in ability to control and somewhat deprived in terms of creativity. They have a bunch of hard working decent all rounders but none who are anything special with the ball at the feet. It means in the games where their attack is stifled the midfield will struggle to provide an edge. Also, as we saw vs Real Madrid (and us at times and Tottenham), when the press slows down they're incapable of controlling the game through intelligence. This was less of a problem with Dortmund. Keita's a good addition, a very good player in fact. But he serves as an upgrade on what they already have and doesn't bring anything new to the table. Much of muchness if you will. Fekir could help out you'd think on the latter, but not only will it take time for him to fully settle (maybe he won't) it's still not enough for him on his own.
- The style of play: This style of play they have will be favourable most of the time. They have an advantage over any team that dilly dallies like us or Arsenal sure, and also over any overly defensive side providing they grab an early enough goal. But any well organised defence can cause them huge problems if they don't score early. Again, they're not good enough on the ball to keep you pinned back once the press slows down and this is their undoing. We've seen against every big team this season, between the 30-45 minute marks and the 60-90 minute marks they've been seriously overrun. The fact is, fundamentally they're set up like us to deprive teams of chances through holding the ball and when this breaks down they can defend poorly like we do occasionally do too. So when this breaks down for extended periods, they're always at a risk. This is a side effect of their poor midfield, but in reality any midfield they could muster would lack this problem.
- No depth up front: Most specifically, Salah and his goals; and Mane and Salah's movement. Firstly, the obvious, there's only three of them and they play all of them at once. We've experienced something like that with strikers at times. They are incredibly reliant on Salah for goals. That's obvious. They are incredibly reliant on Salah and Mane for pace and movement in terms of attacking spaces and defensive lines. They are reliant of Firmino for his pressing. Take one out, and all of a sudden things go wrong, like last night. Without Mane, they lack energy and directness (their form after the 5-0 loss to us when was sent off was poor). Without Firmino, they lack sustainable pressing incentive and coordination. And without Salah, they're no better than what they were two years ago. Unfotunately, Firmino isn't enough of a natural goalscorer to make up for his numbers. Also, without Salah serving as a link between midfield and attack at times, Firmino can become isolated as we saw against Madrid. Again, Fekir could help out here, but then that'd nullify any potential solution to their midfield problem.
- The Tottenham problem: They have no winners in their team. They have no experience ruthlessly winning a league. They have won one trophy in the last decade, and most of this bunch weren't there at the time. Chelsea haven't had that problem over the years which has meant that any manager that can come in and motivate them gives them a chance.
- Salah: Can he do it again? It's likely he'll score a lot again, but to this extent?
- Injuries: Midfield injuries was their undoing as the season wore on. But combine with all of the above can they handle it if an attacker goes to the doctor's room for a lengthy period.
- Right back: They're still weak at right back.
Their only hope is that they sack off the CL completely and focus on the league, pulling a 16/17 Chelsea; but I doubt that'll happen.
And United. They finished second, despite playing largely poor football, having individual players play poorly and with a large feeling of discontent. The reasons why they might not threaten again are obvious. They just repeat all of the above, with an added dose of potential in house anarchy, as is Mourinho's trick. But then you wonder, if they could do it and finish second and make a cup final with all that crap, couldn't they do better with a couple of good new additions? De Gea is likely going to carry on bailing them out, but that could be a difference. Remember, they don't need to beat us to win the league. They have a certain mentality and physicality that means that with Mourinho the manipulator at the helm they always have a chance of winning any game. Now with the added motivation of taking down City and Pep he might just do it. Like Conte, he has form for league successes in the past and he's amassed 100 points before. He has that gift that Ferguson had of turning shit into success and having them win one game at a time, and if we're as long as they're near us in the table it'll keep them going. United would also have the backing of the powers that be on their side, probably.
I can't see anyone but us hitting 95 points next season. So if we can hit that we'll be fine regardless. I doubt we'll feel the pressure of being in a tight race at any point, last season should serve as motivation.