Results from the Editor Review (Upgrade Path Issues Only):
1) Impi (the African Spearman Flavor) upgrades to the Inti Warrior (the Incan Warrior Flavor). The correct upgrade would be "Pikeman".
2) Several other issues involve the Inti Warrior. Although technically the Incan Warrior Flavor unit (it's Tech Pre-req is "Warrior Code"), this unit is extremely overpowered at 4-2-2. It seems a more likely candidate for the Medieval Infantry Group, and this may have been the original intention since it upgrades to "arquebusier". When and if these fixes are made, be sure to also go back and insert an Incan path from Warrior to Swordsman to Inti Warrior.
3) The Commando line ends at Spetsnaz. Should it continue on to Shadow Force?
4) Light Artillery is a mid-20th Century dead-end. Technologically speaking, didn't this evolve into man-portable rockets, ala TOW Infantry?
5) The Fighter line ends with Harrier. Should this link to Advanced Fighter? (Which otherwise appears from nowhere - nothing else links to it.)
6) As previously discussed, the Templar unit has no upgrade. Would it make sense for this to follow the path of other religious-type units (such as Crusader) and upgrade into the Patriot line?
Major Issue: When the Units were set up in the editor, flavor units were linked together in an upgrade path in such a way that only one of them contains the REAL upgrade link (i.e. to the next generation of unit). Because of this, the Civilopedia will only show an upgrade path for ONE of these units. For example, let's examine the 11 flavors of the Spearman Group - Spearman (generic), European, Germanic, African, Asian (Otomo), Arabian (bad-linked as "Eastern" in the Spearman civilopedia entry), Javelineers, Hoplites, Numidian, Impi, and Immortals. Only one of these (Germanic) contains the upgrade link to "Pikeman". Another example - even more convoluted - is the only link between the Warrior Group and the Swordsman Group (from "champion" into "Frankish Axeman"). Which isn't intuitive, to put it mildly.
Unfortunately, this means that if the civilopedia is ever going to include upgrade links for all units, the only solution is to go back into Units editor and change all the upgrade links. Using the Spearman example from above, that means all 11 flavors would have to link directly into "Pikeman".