They are fishy. I suspect that it is the League and CL batches and draws that gives an indication of how your team will perform in relation to the quality that you have. If you have been put in a batch consisting of low quality teams, the percentage efficiency of your team has already been reduced (hidden, but this may not activate or be apparent immediately). It could be to compensate for the big difference. You must be careful when facing those significantly weaker teams. While you may get a lot of large wins, especially at the start, you might struggle against a weaker team in the later stages despite having much higher visual quality displayed for your team. And if you have not used the best tactics, you will be knocked-out. Sometimes, even with the best tactics, you may get knocked-out. This is where I suspect match fixing.
Take into consideration that the above have not been proved 100%, but many indications are there. Sometimes, just by looking at the batch you have been put in, you can already say how efficient your team will be in terms of quality throughout the season. What is displayed, that is what you see is not always what actually there is. A 5 star team is actually a 3 star team if it is set to 60% efficiency. This is a very significant effect.