I would argue that since abilities came before class back then, that any individual who rolled a 17 or 18 in constitution or rolled an 18 in strength and did not choose a Fighter* was making a very curious decision. The massive gain from that special class ability was huge.
In fact, I would argue that your question is kind of strange, simply because you wouldn't see a cleric with a strength of 18. If you had an 18 in strength, it would be really .... odd ... to not choose a fighter. I can't say it never happened, but ... I never saw it happen.
*Before you respond, read the disclaimer. This includes subclasses.