- Formation is available on drill II, yes.
- Drafting is less

expensive than whips and just as importantly does not stack with whip anger.
- Unless you are spain, cuirassers are a poor unit defensively and too expensive for that role.
- Cuirassers require both iron and horse, oromos require neither
- Whipped or upgraded cuirassers complement drafted oromos nicely
- However, oromos also complement a continued medieval war follow-up nicely, and MT isn't necessarily close in that case.
- Blasting weakness of drill to knights is like blasting the weakness cuirassers have to pikes (either you take spies into every single city or the pikes will have winning odds on you). It doesn't make sense in a vacuum and there are obvious workarounds in both cases.
I see little justification when going cuirassers and having mandatory access to both nationhood and muskets to avoid drafting entirely. Even stock muskets should be a factor of some kind in a cuirasser war; they're just easy to access. The UUs have extra utility.
Entirely subjective and irrelevant.
Boring is subjective, earlier win is not subjective; that is either true or untrue and might be map-dependent.
None of this is to say that I feel oromos are a top tier UU; that's the land of quechas, chariot UUs, prats, and keshiks. However, they have enough utility in the general sense (and are available off one of the strongest mechanics in the game) to be a solid UU on a consistent basis, which is more than Willem's UU can say (it's either absolutely spectacular or useless typically).
but it is still one of the best UBs out there, and goes great with being FIN.
I don't see how such a case can be made

.
- Terrace
- Hammam
- Ball Court
- Odeon
- Ikhanda
- Sac Altar
- Ziggurat
- Ger
- Rathaus (too bad you have to pay the price of awful starting techs, a bad leader and iffy UU)
- Hippodrome or whatever (Byzantine)
You could also make a case that the cothon, mint, garden, baray, and even the totem pole sees more impact on the actual outcome of the game on average, simply because they are actual factors when it might still be in doubt much more frequently. "Average at best" =/= "one of the best"

. All of the above share early availability relative to the dike, and some stand a reasonable chance to provide more impact even before PV considerations, especially considering that the dike can't provide useful returns everywhere (on a decent chunk of maps its productive boost over standard levees would maybe scratch that of a stock exchange lol).