Regarding impossibility is debatable because Liverpool can misfire too. After all, Manchester City looked very good at first, but at a certain point started losing. Liverpool are not immune to this either, some key player gets injured and stability will be lost, they will have to change tactics and rebuild the squad, it will not be to their advantage. On the other hand they really need to stabilise first before thinking about first places
Regardless wether Liverpool misfired at some point or not, Manchester United will never come close to Liverpool in terms of point on the premier table for the rest of this season so we shouldn't expect much from Manchester United in this season not to the level of comparing them to a club like Liverpool in this season, Liverpool have secured themselves a good position that can not be easily dashed out, and being a club that have suffered a lot of set back in the past seasons, and haven't been so very lucky to have succeeded in clutching to the first spot on the table from the beginning of this season, Liverpool is quite on the verge of lifting this league this season.
Even as we have not gone far in this season, we can tell from the records so far that there is a lot of things to be expected in this season, but still on that we can point out the clubs that have that potential to deliver from now on, because as for Manchester United already there is an internal crisis with the club and at this point we can only point them to be able to finish tgis season among the top 10 club's, but their cant make top 3 again, so it a fight between Liverpool and clubs like Asernal or Manchester City to compete for this season championship and premier league respectfully.