Brighton will not be able to keep up with Arsenal's game in the second half, this is clearly difficult to do, we know how difficult it is to penetrate Arsenal's defense, even in attack Arsenal look aggressive, maybe in the second half the goals will increase again, while Brighton is still not sure they can do it.
Brighton is only good at the beginning of the season after that it starts to dim again, sometimes this team always does not last long because there is no strong experience throughout the season.
The match against Manchester United was very challenging for Liverpool. Klopp must instruct the players not to fail to get points in the away match, otherwise Arsenal will really lead with a 1 point advantage. Manchester United are not in great form after losing against Chelsea, but they are playing at home which will probably keep the players well motivated. Liverpool must be careful, of course.