ac196nataku
Noob
I noticed that some UU's don't seem to upgrade logically. They seem to be due to the expansion packs (either new UU's or new units messing up upgrade tree). I know the civilopedia is no longer 100% accurate after the expansion packs, so I assume the expansions were a little "phoned in".
Zulu Impi (1.2.2) upgrades to Musketman (1.4.1).
I guess you might want to keep Impi's around if you use them with Horsemen, but Knights have one more point of defense than Impis.
Carthaginian Numidian Mercenary (2.3.1) upgrades to Pikeman (1.3.1).
This one makes no sense at all. Pikeman have one less point of offense and require iron. The Greek Hoplite (1.3.1) already skips over the Pikeman.
Persian Immortal (4.2.1) upgrades to Medieval Infantry (4.2.1).
This one probably just got lost in the cracks when Medieval Infantry were added to the game. The units are exactly identical except the latter costs 10 more shields.
At first glance I thought the Dutch Swiss Mercenary was identical to the Musketman, but I since realized the Musketman has one point more of offense. Personally, that's not worth doubling the cost, but there's precedent for terrible upgrades in the game.
Since I play with tweaked rules already, I decided to fix these upgrades in my game:
Impi to Pikeman.
Numidian Mercenary to Musketman.
Immortal to Guerilla (6.6.1).
Do these odd upgrade paths bother anyone else? My only concern is that maybe allowing Persia to build a 30 shield 4 attack unit for basically the entire ancient and middle ages is a large advantage.
Zulu Impi (1.2.2) upgrades to Musketman (1.4.1).
I guess you might want to keep Impi's around if you use them with Horsemen, but Knights have one more point of defense than Impis.
Carthaginian Numidian Mercenary (2.3.1) upgrades to Pikeman (1.3.1).
This one makes no sense at all. Pikeman have one less point of offense and require iron. The Greek Hoplite (1.3.1) already skips over the Pikeman.
Persian Immortal (4.2.1) upgrades to Medieval Infantry (4.2.1).
This one probably just got lost in the cracks when Medieval Infantry were added to the game. The units are exactly identical except the latter costs 10 more shields.
At first glance I thought the Dutch Swiss Mercenary was identical to the Musketman, but I since realized the Musketman has one point more of offense. Personally, that's not worth doubling the cost, but there's precedent for terrible upgrades in the game.

Since I play with tweaked rules already, I decided to fix these upgrades in my game:
Impi to Pikeman.
Numidian Mercenary to Musketman.
Immortal to Guerilla (6.6.1).
Do these odd upgrade paths bother anyone else? My only concern is that maybe allowing Persia to build a 30 shield 4 attack unit for basically the entire ancient and middle ages is a large advantage.