In my own list this is how I rank em up;
1) Real Madrid
2) Manchester City
3) Bayern Munich
4) Inter Milan
5) Arsenal
6) Barcelona
I do think that Porto would be tough on Arsenal but they'll qualify ahead of them to the next round. I remember the last club that knocked them out of the Europa League Competition last season was Sporting Lisbon. As for Barcelona, they're one team with lot of inconsistency. Could they defeat Napoli? They could finally do that but they will not escape if they fail to sign up a good defensive midfielder. According to Cristiano Ronaldo, Manchester City are his number 1 option to win the Champions League Competition.
For 1, 2 and 3 I agree with you but I will put Barcelona in 4th position and Arsenal 5th position while Inter Milan is in 6th position, Barcelona performance is not very impressive this season but they can be relied on in important tournaments like this or even Barcelona can reach the semifinals while the final will most likely be between Real Madrid vs Manchester City. By the way, where do you place PSG? they managed to get through a difficult group even though the results are not perfect, PSG still needs to be watched out for, because usually PSG often reaches the semifinals moreover, Mbappe is still there.
That's the correct list, but for me more precisely, Barcelona is in 5th position and 6th position is filled by PSG.
The reason I say that Barcelona is more worthy of being under Inter is because I judge it not from experience, even though it is very influential, but I judge more from the performance of the current players. better quality and this is a fact.
Next, why do I want to replace Arsenal with PSG because in terms of consistency, for me, PSG is more consistent and stronger, while Arsenal has inconsistent performances, even being in the Premier League, Arsenal having a bad time.
All this is just speculation that I have, maybe we have different opinions but Manchester City will still be the CL title holders this season unless they experience injury problems to the players which will cause big problems.