You are right. PSG has the ability to win against Liverpool. PSG is a very strong team. But Liverpool is very organized this season. And Liverpool's overall performance is also stable. I have seen Liverpool very tactical and capable of playing well against big teams. We saw Liverpool's excellent gameplay a few days ago against Manchester City.
Liverpool should be considered the favorite against PSG. But we should not forget that PSG is not a weak opponent. PSG has the ability to win. If Liverpool does not perform well or if Liverpool's defense is weak, PSG will win this match. But if Liverpool's overall performance is stable, the chances of PSG winning are very low.
Liverpool and PSG are big clubs with many good players but Liverpool have better players and they are more experienced and successful in Champions League than PSG. Football is never like math so Liverpool despite of fact that they are stronger, will not get any certain winning ticket to quarter final phase. They must fight for that ticket and will have enough big challenge from PSG that is an ambitious club.
PSG after many years of big transfer budget spending and failing in Champions League, will try in this season and each of next seasons, to win this title. They definitely won't feel happy to face with Liverpool in round of 16, that is too early, but they accept this challenge and they know that if they beat Liverpool, they will feel more confident and can make history in this season.
Atlético Madrid's opponent in the Champions League is Real Madrid and I think they can beat any team if they can overcome the barrier they have in the Super Sixteen. One of the most experienced and strongest teams for the Champions League is Real Madrid. Real Madrid has performed poorly in the local league in a season but they are doing well in the Champions League.
Atletico Madrid are never an easy opponent for Real Madrid in La Liga and Champions League. It is classic of any derby in football, even you are a stronger team, you might fail in a derby match. Atletico Madrid in this season are not weak by showing their quality, strength and competitiveness in both La Liga and Champions League. They lead Real Madrid in La Liga and are ready to beat Real Madrid in Champions League as well.