Guardiola made a good strategy to face every opponent that is in their way to get the treble winner this season, I don't think Intermilan can be seeded against Manchester City even though the Odds for Intermilan are very high and tempting because they have a chance to win because they are playing in the final.
I also think, that if nothing completely crazy and unforeseen is happening in the final of the Champions League, then Manchester City should not have to many problems to finally win this competition after being one of the best teams, if not the best team in the world of football for at least 3 or 4 years now. That being said, it is a final and only one game and there everything is possible. A lucky goal for Inter Milan after a corner or a freekick or something and then the whole game changes.
Also i think that Guardiola sometimes has the tendency to "overcoach" and overcomplicate things in very important games. I hope he just lets his team play as usual, then everything should be fine.