Suave's comment , ".....proves the game is even more balanced than at first glance...." is an intriguing one. Grendels' Ranking and comment kind of set the stage. like a reference point.
At a certain level , one might be able to accurately rank the Unique Units according to position and game conditions.
(Not just map size or level- also oppossing civs, terrain, ur mood)
That being the case , and -with a tip of the hat to Grendel's reference point and grouping- ie (the A's, the B's etc.) Here are some comments about UU's.
Conditions-MP 2-3 hr (Elim or not) Tiny Pangea (or not)
Defense-Jungle, mountains +
Numidean/Hoplite : excellent, build walls and u won't die, but will u win? Numideans do alot. If they are allowed to build. Kill them quickly if u are given the chance or at least get in thier face.
Attack- Plains, desert +
War Chariot, Immortal, , Mounted Warrior, Impi, Jaguar,
Some u wait on some u don't , but the key is when to start pumping them out, noticed Aztec can go broke quickly so wait, take it easy, even with the immortals-but once given the go, produce them like hornets out of the nest. To fight these, get defensive units in their face, or on ur mines.
Bowmen , Legion*-played them only sp, Others That Come in Med.
Waiting is always what these civs tend to do, watching others war and building up, which makes sense. I like bowmen yet at times they can be really weak, failing against warriors. To fight them i suggest u pillage. If u are them u have the option of attacking or defending. Make up ur mind and do the best u can at either. Don't do both, u'll lose. I asked over the chat which people preferred , Celt or Legion and Legion won because of cost.
I like the Celt tho- scout, attacker, counter-attacker, run awayer,
but i suspect there are legion players that can dominate given the chance, and too, i will add this, played SP -Rome on Emperor and quit because i had dominated so early....