Wodan
Deity
Been thinking about strategy instead of tactics lately. Here's my contention: many early and midgame UUs (e.g., Praetorian) are not suited to be used as effective offensive units and conquer significant territory.
Here's why: you need an effective infrastructure to support significant territory expanses. Such infrastructure is not possible without markets, banks, etc. These buildings need midgame tech plus time to build them.
If you conquer significant territory before you have the infrastructure, then you get way behind in tech and effectively lose the game. That's why many Roman players have a tough late game. Using those Praetorians is just too hard to resist.
Now, that's not to say you can't use an early UU to get moderate increases in territory. Say 25% (2-4 additional cities). That's actually your best move.
Also, that's not to say you can't use your UU in another role. e.g., defensive (so you can build minimum military and focus your production upon infrastructure), raiding (hamstringing your neighbors by pillaging their improvements), or gifting your UUs to prop up weak AIs who are in war against strong aggressive AIs.
Likewise... there might be other effective strategies: "think outside the box" strategies. e.g., use Praetorians to raze, not conquer. Effectively wipe clean the planet, except maybe a city with Pyramids and such. Sure, barbs will be a problem, but your Praets shouldn't have too much trouble. Ditto on Cho-Ko-Nu and most other UUs in this category.
I'm not saying you can't win the game on a high skill level, just that it is never going to be as optimum as having a good UU come into play after your infrastructure is built. Cossack etc will provide a more optimum game than Praets etc. Yes, you have a smaller territory with your core infrastructure, but you get your core infrastructure built earlier, and you get techs such as Military Tradition earlier, and you then can more than double your empire and have a successful bid to conquer the world in the middle ages. Even if you don't manage it, you are almost assured of a late game conquer win.
Finally, some UUs come too late to be effective in a bid to conquer. By that time, your success or failure is determined by what has gone before. The UU will aid you in what you are doing anyway, but you won't win because of the UU.
So, here are the UUs I think are suboptimal: Camel Archer, Cho-Ko-Nu, Conquistador, Immortal, Jaguar, Keshik, Phalanx, Quecha, Samurai, Skirmisher, War Chariot
Here are the UUs which are superior: Cossack, Musketeer, Redcoat
Non-factors to this discussion: Fast Worker, Navy SEAL, Panzer
Wodan
Here's why: you need an effective infrastructure to support significant territory expanses. Such infrastructure is not possible without markets, banks, etc. These buildings need midgame tech plus time to build them.
If you conquer significant territory before you have the infrastructure, then you get way behind in tech and effectively lose the game. That's why many Roman players have a tough late game. Using those Praetorians is just too hard to resist.

Now, that's not to say you can't use an early UU to get moderate increases in territory. Say 25% (2-4 additional cities). That's actually your best move.
Also, that's not to say you can't use your UU in another role. e.g., defensive (so you can build minimum military and focus your production upon infrastructure), raiding (hamstringing your neighbors by pillaging their improvements), or gifting your UUs to prop up weak AIs who are in war against strong aggressive AIs.
Likewise... there might be other effective strategies: "think outside the box" strategies. e.g., use Praetorians to raze, not conquer. Effectively wipe clean the planet, except maybe a city with Pyramids and such. Sure, barbs will be a problem, but your Praets shouldn't have too much trouble. Ditto on Cho-Ko-Nu and most other UUs in this category.
I'm not saying you can't win the game on a high skill level, just that it is never going to be as optimum as having a good UU come into play after your infrastructure is built. Cossack etc will provide a more optimum game than Praets etc. Yes, you have a smaller territory with your core infrastructure, but you get your core infrastructure built earlier, and you get techs such as Military Tradition earlier, and you then can more than double your empire and have a successful bid to conquer the world in the middle ages. Even if you don't manage it, you are almost assured of a late game conquer win.
Finally, some UUs come too late to be effective in a bid to conquer. By that time, your success or failure is determined by what has gone before. The UU will aid you in what you are doing anyway, but you won't win because of the UU.
So, here are the UUs I think are suboptimal: Camel Archer, Cho-Ko-Nu, Conquistador, Immortal, Jaguar, Keshik, Phalanx, Quecha, Samurai, Skirmisher, War Chariot
Here are the UUs which are superior: Cossack, Musketeer, Redcoat
Non-factors to this discussion: Fast Worker, Navy SEAL, Panzer
Wodan