Well said, Jitty. 
I like to think the Khitomer Accords imposed some limits on cruiser numbers and tonnage for both sides, not unlike those post-WWI treaties that eventually got ignored, so the Federation decided to go ahead and replace their Connies with Excelsiors but were able to keep the Mirandas in service because they couldn't come up with a better Miranda design. (The Centaur might have been a try.)
So the Connies and Excelsiors would be a lot like all those B-52s the U.S. built for the Cold War, most of which have been scrapped by now. The difference between the two classes being that the Excelsiors were new enough that a lot of them were either still in service or had been mothballed and could be quickly reactivated for the Dominion War.
Also, there was that one wrecked Constitution at Wolf 359, and the wreckage of the Olympia in "The Sound of Her Voice" - both of which were apparently reuses of the TSFS destroyed Enterprise. Clearly at least two of them made it to the 24th century, but if we take proportionality into account, I imagine there weren't many more.

I like to think the Khitomer Accords imposed some limits on cruiser numbers and tonnage for both sides, not unlike those post-WWI treaties that eventually got ignored, so the Federation decided to go ahead and replace their Connies with Excelsiors but were able to keep the Mirandas in service because they couldn't come up with a better Miranda design. (The Centaur might have been a try.)
So the Connies and Excelsiors would be a lot like all those B-52s the U.S. built for the Cold War, most of which have been scrapped by now. The difference between the two classes being that the Excelsiors were new enough that a lot of them were either still in service or had been mothballed and could be quickly reactivated for the Dominion War.
Also, there was that one wrecked Constitution at Wolf 359, and the wreckage of the Olympia in "The Sound of Her Voice" - both of which were apparently reuses of the TSFS destroyed Enterprise. Clearly at least two of them made it to the 24th century, but if we take proportionality into account, I imagine there weren't many more.