^ I agree with what you've said there and a full scale war with the Feds would have reduced Cardassia to a minor league player, hell even the all mighty Klingons and Romulans where sore afraid of large scale war with the UFP and it has been implied that they would lose such a war.
Now judging from what the Klingons had to deal with when enaging the Cardassians I think that the Cardassian's would have had better tactical planning than starfleet and it seems that their ground forces are superior to the redshirts. So it would seem Logical
to think that Starfleet would suffer serious losses in both liberating Bajor and defeating Cardassia's Military/Industrial Complex(basically dismantling the whole Union), plus because the Obsidian Order is still around the Cardies will enjoy greater Intel on Starfleet than Starfleet would have on them.
However... the Federation has more resources and Starfleet enjoys a Technological advantage which along with the ever present writers fiat means that the UFP would be victorious over the CU in the event of an all out war. ( and if they can keep the Klingons out of the war, then Millions of people would not be massacred during the course of the War).