Agree. I don't see any reason to consider chelsea as too strong. We have seen many times in the last season that the team failed to play well against smaller teams. In the semi- finals , Chelsea will face a team whose performance surprised us all.
Chelsea couldn't be seen as a very strong team obviously because its record in domestic and international competitions and the team's results were always fluctuating.
Fluminense is just being seen as a weaker team in a lower league, otherwise they have the chance to overtake Chelsea like their own Brazilian rival in the group stage.
Personally I am going with Chelsea victory whether in the main time or after extension to penalties.