Their game is always on the edge as as soon as they concede two or more goals, their whole game plan is in vain since they usually don't score more than one goal. But to be honest this isn't something that can quickly be fixed and if they only have the resources and players to focus on one thing over another, I think sticking to a strong defense is the best they can do. If they can then gradually improve their offensive game over time as well, then it is even better. But for the time being I believe Nice will remain the team scoring a low number of goals while also conceding not a lot of goals.
PSG having most lethal attack in French league and with this they can ruin any team, but their defense is also conceding goal which is also created problems for them but still currently they are at the top and having enough chances for staying at this spot but now Nice which is currently second but having the least goals in top ranks with just 19 goals from their 17 games mean they are not going to challenge leaders and if they want to have better in second half they need to improve this and having quality striker which will give them good confidence and improvement which is also important for them otherwise things can take good change, and they can go into problems with second half never been easy for any top team which is also wants to stay in touch for the European connections.
But the imbalance between their offensive game and their defensive game has been PSG's biggest problem ever since I know the club and ever since I have been following their games. Their offense has never really been a problem, but the issue was that their defense was out of balance because they afforded three players in their attacking line that never did defensive work. I think in modern soccer no team can afford three players of the same type who are just waiting at the midfield line to get the ball and start an attack. If you look at players like Lewandowski or Harry Kane, the effort they put in to help their defense is incredible. A team may have one player like Mbappe who is just waiting for the ball, but PSG often had three of them.