Yes, with Greek, you have a "slow" civilization, that is, a civ w/o any economic bonus. Worse, their best unit (centurion) is slow, expensive, and easily converted. Also, they have no effective military until iron, which they will rarely reach.
Why?
No economic bonus, plus no archer support (for home defense or troop escort, not to mention the ability to raid & kill vills) = speedy death. Besides, no opponent is going to let Greek get to Iron (and get centurions) if they can help it.
Another issue is their gold dependency - without any economic bonus, this also spells doom for greeks. From the bronze age on, the greeks have no land units that do not require gold. (The only post-tool age, non-gold-eating unit the greeks possess is the galley/trireme! But, hey, at least it's FAST!)
Here's another interesting feature. Most agree the Greeks were at the bottom of the barrel in AoE, so what did that sympathetic group at ES do for Greek in RoR? Hey, RoR gave us FIVE new units! And they gave the Greeks... ONE. Yup! No camels to help offset a pathetic bronze, no fire galleys to protect those fast triremes, no scythe chariots to give them a worthwhile, Iron Age non-gold eater, and of course, no Armored Ellephinx (since they had no elephumps to begin with).
But, HEY! They got slingers! Woo-HOO!
It doesn't stop there. Take Death Matches. I don't play them, so any DM'ers who can tell me where I'm wrong with this observation may certainly chime in. But why would you play them in DM?
Their best unit, the centurion, is still easy prey for priests and HHA's. Sure, they get full seige, but if you want seige, you want Hittite muscle or Sumerian firing speed. Or Roman, who also gets full seige, improved bowman, and scythes! And, of course, the gold issue! It's still a finite resource (w/o trade, which is inefficient and far more dangerous, not to mention resource-intensive). No scythes!
Sorry... if you want a challenge, if you know you're superior to your opponent, or if you have lost your job, your mate, your dog, and just want to end it all... Greek's the One!