It is also possible that neither side committed any real forces to the fight.
That is very possible too. More a skirmish or cold war than a hot one could have occurred. Truth is we don't know. I was offering a possible explanation. I was speculating that the Cardassians were once an expanding empire until they ran up against the UFP, a level of power they had not encountered before. After fighting a long, bloody, and costly war, this could account for Cardassia's power waning, after the Border Wars, and as mentioned before, the reason Cardassia had to withdraw from certain holdings, like Bajor, because they simply couldn't afford to do it any more. That is what tells me that they may have had a strong military, but no industrial or economic means to sustain it. Once the military was depleted, they became a second rate power because they couldn't supply that military to pre-war status.