Anderlecht were only made to look like one of the better teams back then because they were in the European Cup every year because they kept winning their backwater league and got to the latter stages of the European Cup because they were coming up against even worse teams. Would they have been a very good team back then if the European Cup featured the top few Spanish, English, German (not East Germany who regularly sent canon fodder to the European Cup, i.e. Dynamo Dresden) French, Italian and Dutch teams? Of course not.
It was technically the number one competition but everyone knew the UEFA Cup was the tougher competition. The UEFA Cup was the people's cup. Imagine the Champions League and Europa Cup having the same format in 2014. I know which competition I'd want to watch.