Look, don't confuse Catholisism with Roman catholisism. The time period of about 600AD had only one schizm in the church, and that was between Rome and the Eastern Orthodox. The Western Church was still called the Catholic church. What I'm saying with Bishops and all is, is that it is almost exclusively a Christian institution, or at least was so at such an early time. The evidence I have for this parallellism is just as solid as any of the other scientific ones that have been thought of and taken true on this site. If you wish to speak of "intent" and what "it was based on", then 95% of what ZeaLitY has thought up would be wrong, because even the original designers didn't think that far. But he has made logical inferences based on what is shown, and his theories are considered acceptable and true, as there is nothing in either game to disprove them. Even so, this historical theory of mine, though it might be considered far fetched by you, has no basis to be rejected. Just because no mention is made of Christ does not mean that in that He does not exist in the Chrono universe (and, again, if you wish to bring up intent of the designers, being Eastern and such, then many of the things that have been so painstakingly been charted out would need to be dismissed, for they were not intended originally, either.). Even so, I would beg you to dismiss my theories based on evidence in the game (in which case I will revise my theories; not for my story, though, for that is simply literary style to further the story, but in regards to this thread, I will revise it.), rather than just opinion, for in that matter the only thing that you have going for you is that it likely was not the designer intent (which has often been overlooked, anyway). As any true theory, it must at needs change if contradictory matter is found. Yet I have found little of that, save in some of the areas that CT and CC themselves are at odds on.
In the end, to your question, I would say, yes, the Chrono universe is somewhat of an alternate split future, save perhaps with the exception of Lavos. That is an interesting quirk, which is likely the splitting trigger; however, as his arrival is very early on, the true split then does occur at about in prehistoric times. However, based on the hibernation of Lavos for such lengths of time, no great change occurs for a great period of time, or at least none readily noticeable. Some will maintain that Zeal and the Dreamstone are products of Lavos, but that to that I have two replies: firstly, I still maintain for lack of ironclad evidence to the contrary that the Dreamstone is a thing of this world. The second is that Zeal is so ancient that its existance hardly affects the ancient world as we know it; even as we hear of Atlantis as but a myth, and it hardly affects us, so too is it with Zeal (which is perhaps that dimensional equivalent of the Atlantean civilization). What I'm basically saying is that, even as Tolkien's Middle Earth can be taken as a prehistory to this world (circa. 5000BC), as he intended, so too can Zeal be looked at in such a light, filling in the shadows of history, though having no absolute bearing on later generation, save in unnoticable echoes of history. Now, not to say that at all points the development of the real world and the Chrono world coincide (as I have said, the true split is likely a prehistoric time), but the similarities even in the differences come together to forge a similar "middle age" as it were. We have Atlantis (the Theran civilization), they have Zeal; in the end, both amount to the same end. They have a flood due to the fall of Zeal, we have a flood attributed, in the Christian tradition (and many others) to the wrath of God. Both events wipe clean civilization. Both bring about a dark age. Thus the state of our world and the Chrono world circa 9000BC is not that different, and I can fully see those who remain in the last villages banding together to build a walled city such as Jericho. And from then...an equivalent, or nearly equivalent, history. People will invariably band together into cities, and then into empires. Now, I understand that in our world, as there never was a Zeal, the birth of different people would result, effictively changing the names of the kings of empires, and perhaps dictating the empires themselves.*(see below)Again, there is no absolute way of refuting that the history of the Chrono universe is all that different than our own. What I say is that there is insufficient factors to greatly change the course of history in a general sense; it only manifests itself in certain eras. The first is at the time of Zeal. The second, with the rise of the Mystics at about 500AD.
Thus I still maintain my thoery, and beg you to, in true scientific fashion, disprove it with data (which, in all liklihood, is very possible; I'm not maintaining that mine is without flaw correct. Only that, at this moment, I have seen insufficient data to revise my thoery of this).
*note at this point: this is perhaps my only faltering point in the theory. The existance of Zeal and its subsequent fall scatters the seeds of history in a somewhat different manner than in our timeline. My theory is dependent on the non-interference of the survivors of Zeal with the common timeline, which may be somewhat difficult to reconcile. Yet here is my proof that, unlikely as it is, history continued in the same way: Miguel's Latin. It makes the appearance of Rome a neccessity, and the pre-existing absorbtion of Latin and Etruscan tribes by, perhaps, the survivors of Troy (though this last part may simply be fiction created by Virgil). Whatever way it might fall, Rome, in the Chrono Universe, was significant enough to spread influence far to the West, and into common culture. If such a late event is there, then it makes the earlier kingdoms important as well. Thus, unlikely as it may seem, this appears to be the solution: history became unravelled in prehistoric times, but the effects were not apparent. For a time they could be seen in the rise of Zeal, but it came and went without lasting effect, for Rome rises. Thus, scientfically through historical hypothesis, I would maintain that there is a great accordance between the two timelines, Chrono and ours, and that the first standing change is not until circa 400AD.