I don't think Liverpool is stronger than Manchester City. They likely have better tradition and more experience in Champions League than Mancheser City. But about quality, they are at same quality so if Real Madrid can score goals and beat Manchester City, they will be able to beat Liverpool.
Mane and Salah can score goals but Real Madrid in this season, does not have issue with conceded goals. They can score more goals and break mentality of opponents to get final win.
It might be true that Liverpool is not stronger than Machester, but I think we will see a very different game in the final compared to the Machester vs Madrid semi-finals.
Odds for winning the trophy are Liverpool 1.55 & Madrid 2.35, which is quite balanced considering earlier odds of the semi-finals when everybody thought it will be an easy task for ManCity.
Utlimatively I think Liverpool will win this game, but it won't be an easy task and might go to extra time.