Two things to note:
1) The original analysis was written before CTDS was even mentioned, let alone released. Speaks a little of my abilities to analyze, since I thought Dalton was the least likely but he turns out to be the cause (though I am curious if Kato might have been retconning a bit there).
2) We don't know in what time period Dalton began the downfall of Guardia. Might have been in 1000, might have been in 600, he might have traveled between the two, etc. Thus, he might have taken over Porre before the Mayor we saw in CT ever came to power.
1) yea... ok makes sense
2) Dalton is found in the dimensional vortex, 1000AD, which we know exits to 1000AD. Guardia ends in 1005AD. It's pretty clear that he starts in 1000AD or sometime after.
One might say(to argue against me).. how did he get there in the first place? Doesn't his presence in 1000AD prove that he knows how to time travel?
Sure, but it certainly wouldn't be hard to explain (that he's stuck in 1000AD). He was standing on the epoch when he was sucked into his portal, and originall that's the last we saw of him. Perhaps his proximity with the epoch, Lucca's gate key or the pendant, or all three made the portal end up there. It wouldn't be so difficult to suggest that he was stranded in 1000AD.
But then again, if the makers want him to be able to travel time at will, then that won't be too hard either.