Just because a world has an ancient site doesn't mean the world gets a higher TL. Yes, a lot of non-Imperial TL 15s were lowered to 14 (or lower, depending on the circumstances) because Marc really impressed that TL 15 needed to mean something more. This meant that a lot of the DGP MegaTraveller TL15/16 worlds were reined in. And yes, if this were a different Milieu, and we were running to determine sustainable TLs, there would be substantial changes to a lot of worlds.
The UWP changes across the Trojan Reach were intended to restore it to its canon written status... as a frontier, that a lower TL group of Aslan clans might aspire to conquer.
At TL 15, the Florians should turn the Aslan invaders into atoms; canon tells us it's a difficult, hard fight and the Florians lose some worlds to a series of TL 12 foes. That's more excusable at TL 14 than TL 15.
Canon is more than just UWPs. Canon is also Marc's vision of how the sectors fit together, and how the worlds build and flow. We started with the Second Survey data, then added the Sophont Review, and then realized the Timeline was also part of the same set of materials.
tjoneslo has this nailed down. Sadly, the original Mongoose Aslan book was done just before we started the T5SS project. The UWPs supplied for it are REAL close, but you have the tech decisions, a few other vision points, etc. Matthew is apprised of developments with the T5SS, and I know he envisions incorporating those developments in time.
As to your work on the Florian military, use the UWPs you have and your work in your games. Or if you were working to publish... that we'd have to discuss privately.
