English clubs were dominant in Europe before that 5 year ban because of fan disorder, and they returned to putting in strong showings after it was lifted.
You got me thinking about how strong English clubs were in Europe when we returned. I think your point must be based on English teams doing well in the Cup Winner's Cup on our return, which is fair enough: in the first 6 years back, English clubs won it twice.
However, it really was the 3rd rate European competition and (I had forgotten this) you only had to win 5 rounds to win it, unlike the other competitions. During the pre-ban years of English dominance, it was won by Scottish and Belgian clubs.
Our performance in the stronger competitions was abysmal.
In the first 6 seasons, no English club made it beyond the second round. For the last 2 of these seasons, English clubs "first round" was the group stage, but neither of our champions made it out of the group. Teams eliminating our champions included Rangers, Galatasaray, Legia Warsaw, Gothenburg and Rosenborg.
In those 6 seasons, a total of 13 teams entered the UEFA cup. The best English showing was a quarterfinal defeat, which happened twice. Teams lost 1st and 2nd round ties to the likes of Torpedo Moscow, Trelleborg, Trabzonspor, Volvograd and Brondby.
While we had our moments, I don't think it was a strong showing. When we faced Italian, Spanish, German or even Dutch opposition, we usually lost, though there are exceptions, notably Norwich beating Bayern. However, it's the fact that our clubs were frequently eliminated by Russian, Turkish and even Scandinavian teams that really tells us the standing of English domestic football at the time: we were middle of the pack, vertainly not amongst the strongest.