I actually never played FF7 to completion, as I kind of lost interest after Aerith died. I knew that was coming and wanted to see what the fuss was all about, but it felt like the compelling aspects of the game had petered out by then for me. I was always more of a FF6 guy, anyway -- beat that completely half a dozen times at least. The only FF game that I've completed since 6 was actually FFX, although I got pretty far in FFXII as well.
Wow, tangent on my FF tastes.
Anyway, so I don't know specifically about Knights of the Round and Breeding Chocobos, but I get the gist.
That's not really what I meant, but you could take it to that extreme if you wanted. I was more thinking of when you can face Kefka in his final tower in FF6, as a better example. Basically as soon as you get the second airship in the WoR you can make a go at it, but it will be hard as heck. Seems like I recall level 29ish is about average for getting to the WoR, but since you can't level up all characters evenly and you need three competent for the final areas, that complicates the decision of when to attack Kefka.
I've beaten FF6 with still having some characters in the low 30s on levels, and just a quartet at level 42, and managed to win -- but it was brutal, and required things like the vanish/xzone trick. In AVWW, this would be like being under-leveled for an overlord, but going in anyway -- expect some bloodshed on your part, but if you're very good and have some clever tricks, you can probably do it.
On the other hand, the more "standard" way to win that game is to have all your characters in the 40s to 50s on levels, which is about what you'll have if you do most of the side quests and get all 12 of the characters back and use them in a sliding rotation. Like in AVWW, this would wind up with you having a tough fight, but nothing that is overwhelming to the point of requiring tricks.
Of course if you're super completionist on FF6 and getting lots and lots of the smaller side things, including the best equipment that you wind up having to really put in some battle time for, then you might have all your characters something like level 60+ when you go to fight Kefka. If you do, then the fight is pretty easy, but not exactly two-button easy.
And of course there is the super extreme crazy route of getting to level 99 where you can just have Cyan with the gengi gloves and that other relic that I'm drawing a blank on, so that he does 8 hits with each attack, all for max damage, and Kefka goes down in like three rounds of that. To me, it sounds like the Knights of the Round thing falls more in this category, which is certainly possible in most RPG-inspired games, but it's not what 99% of players would ever do.