I agree with you because football is about strategy and there is no way luck will be enough in the final result. Dortmund and Real Madrid were much better prepared to play in the final and both of them did their best to qualify for the final with very satisfying results. Dortmund's task now will be much tougher because they have to face the king of the Champions League and facing pressure in the Champions League will be much different from the domestic league.
Of course luck is the biggest gift they get and that happens because of the hard work they have done so far. The focus is now on the two teams coming out as champions and we want to see how the two teams can play with more pressure in the final match, so that it doesn't get boring when we watch these considerations.
Of course Real Madrid is not an easy opponent, because I think they rarely lose when they reach the final. Dortmund will of course have a tougher job facing Real Madrid, the Champions League king, who also has a winning mentality. It's not easy for Dortmund to beat Real Madrid, but it's true what you said, football is about strategy and luck, if Dortmund are lucky maybe they can beat Real Madrid, but I don't think that will happen.
I don't think Dortmund can't beat Real Madrid, because they have been able to get to this point, it shows that they have quite good performance, and must be ready to face the king of the Champions League. There is no doubt about Real Madrid's ferocity, even though they are sometimes not good in the second half of the match they always put dangerous pressure on their opponents, so that their opponents have difficulty I think Dortmund should be more careful, because what they are facing is not a team that is easy to beat.