If that stupid top40DB still put in top chart positions, I'd challenge you on that. But they don't any more.
But there is a tendency of some of those stations (we have none in Balto any more) to play 1 hit alot, even of groups that had many. And sometimes, it depends on the trends.
Cases in point:
Righteous Bros - Yes, all their hits were played, but by far the 1 that was preferred was "You Lost that Lovin' Feeling". That is, until "GHOST" came along and then even the oldies stations were primarily playing their "Unchained Melody" from then on.
Roy Orbison - Again, his hits were all played, but the most popular to play was his 1st real hit "Only the Lonely". Then "PRETTY WOMAN", the movie, came out and again, even the oldies stations switched to playing mostly "Pretty Woman", his last real hit (of the '60s).
A hit doesn't mean "#1". Roy Head was #2 on the R&B AND Pop chart for something like 7 weeks. The Beatles beat him out with Yesterday (and I don't know what finally replaced that) and I don't know who had the R&B #1. But it was still a hit and covered by a number of other artists, including James Brown.
If you hit in the Hot 100, you had a hit.
Link Wray is in the Rock & Roll Hall of Fame as a "One Hit Wonder" even though he had a number of charting singles. Pete Townsend picked up a guitar because of that "hit". Bob Dylan still calls it the best instrumental cut ever.