Seems you didn't get me right here, am not assuming PSG in this regard as a small team, the small team i used was in Barcelona match history over the years, that they encounter playing against a small team which beat them, this could be at any league and not that am referring to PSG in this regard.
Also from here, i got what you're saying right, despite they both have almost similar pattern, anything could still happens, just as the same way we had with Inter and PSG, whereby many even thought that Inter is in best position to win, but the result came otherwise, so from the discussion, we may also see Barcelona and PSG to be at almost same form, but don't be surprised if Barcelona couldn't deliver as expected.
I now understand what you were trying to say, I think you are trying to say that Barcelona should not be overrated afterall they have also been defeated by a lower team in the past.
Having similar pattern as I said does but mean that unexpected even isn't possible but you know what, when two team have almost the same play pattern, it is almost impossible for things to go easily for either side because they will know the exact way to tackle each other, so thats part of the point I was actually trying to portrays or make, I agree that football can be surprising sometimes but I still maintain that Barcelona would have not been an easy crack for PSG if they were to be in that finals with them.