Second this quandary. With Ballista Elephants in the lead right now I'd like to know why this is the case.
Because the Ballista is not stronger than a regular WE. As a UU it provides little to no significant bonus over base...really none at all. Furthermore, its "bonus" does not carry forward with upgrade - not that I'd care with that one. Being able to target mounted units in the open field is not a bonus IMO and in some cases a malus. Ballista has for a long time been considered the worst UU by a considerable portion of the community. I'm sorry, but if anyone is trying to sweeten up the Ballista Elephant, you are just talking nonsense. Cataphant warfare is often effective on any level, but that doesn't mean an Elephant UU is good just because it exists when it has no real bonus to speak off. Give it shock promo instead or even just Combat 1 or something and it is a whole different story
In fact, that to me is a significant factor in classifying UUs. Is it a tangible bonus like a physical promotion that carries forward. I factor that and a UU's power in the early game, which is why UUs like Quecha, War Elephants and Praets are rated Top 5.
Conks are rated so high as they receive significant bonus on arguably the top non-UU unit in the game - the Curs - especially on higher levels, including a bonus against its direct counter. Plus it can fortify (defensive bonus).
Although no musket UU would be considered top tier, I like the Oromo the best as, again, it's the only musket that receives actually promos, and good ones at that. Musketeers do have some synergy with Cur warfare, which can be kinda fun, but that is all. Jans can romp on lower levels but their bonus disappears with upgrade. Oromos can actually have value on higher levels. Drill 4 is awesome and not hard to achieve out the gate with Civics or settled GGs. Oromos plus trebs or cannons is an effective combo on higher levels. Then you have Drill 4 + whatever Rifles>Infantry so on.
Tatran said:
In my space games (Hemispheres : 2-6 continents), the most decisive unit is the infantry.
Horse based early UUs have the same problem, either the resource isn't available on your continent or it's too faraway to have an impact on the early game.
Infantry? C'mon..the key to good space game is grabbing as much land as early as possible. Good early UUs or effective early combat is far far far better than waiting for things like Infantry.
It's very rare not to have access to horse by the time Curs roll around.