Sulla was a betatester of C3C and wrote interesting statements a long time ago - but not all of his statements are completely fitting. He didn´t take into account, that the production of units in C3C can be effectively limited to small numbers by setting these units to be only produced by some buildings in a low rate. What in big numbers is poison, in low numbers can work as medicine.
Sulla was very specific in his singling out the Statue Of Zeus as The Big Mistake, and for more than one reason:
"7) The Statue of Zeus: I could extend this discussion to all of the wonders, but the Statue of Zeus stands out as such a huge problem that it can stand alone by itself. It's almost funny to think about how silly the wonder was in its original conception. The Statue of Zeus was going to give you a free barracks in every city on the same continent - same as Sun Tzu's - only it would expire unlike the latter wonder and be available much earlier and much cheaper. This proved to be confusing, and so a new unit was created and its function changed to its current state. It has always required ivory to build though, which is half of my complaint. I don't have any problems in theory with requiring a resource to build a wonder; needing "stone" to build the Pyramids in the Mesopotamia wonder seems logical to me and doesn't bother me. The problem with the Statue of Zeus is that it uses ivory as its resource requirement. Ivory is a luxury resource. Luxury resources almost always "clump" together, meaning that is probably one and at most two locations in the entire world where ivory can be found. What this usually means is that by dumb luck only one civ will be able to build the Statue of Zeus. Now if this wonder came along in, say, the Industrial Age when trade routes had already been formed and every civ could conceivably have a chance to trade for ivory to build it, that would be one thing. Making the Statue of Zeus an Ancient Age wonder essentially limits who can build it to dumb luck, and that is not a good thing. I would have raised this issue more in testing, but I never started next to ivory and thus never really saw what this wonder was like. At the time, I was trying to explain why adding more than 8 luxuries to the game would break its happiness model (yes, tobacco/bananas/etc. were all originally luxury resources - I played one game in which there were 11 luxuries! The fact that the designers didn't realize that that would break the happiness model should tell you something...)
So first of all the Statue of Zeus is problematic because of its resource requirement. Secondly, it is drastically underpriced at only 200 shields. This is cheaper than almost all of the Ancient Age wonders; it's cheaper than the freakin' Oracle, for goodness sakes! Knowing what it does, it should definitely cost at least 300, if not 400 shields. Third, it expires much, much too late with the discovery of Metallurgy. A player can research almost all of the way to the Industrial Age without discovering that tech; either Invention or something around Education would be a better bet. Finally, the Ancient Cavalry units it produces are simply too strong. 3/2/2 AND +1hp?! I mean, are you out of your mind? And you can build this thing upon discovering Mathematics? Each Ancient Cavalry is a Gallic Swordsman with an additional hit point; since Gallics were appropriately priced at 50 shields (and are way too cheap at only 40 shields), we can figure that the ancient cavalry is worth about 50-60 shields. We can reasonably expect the Statue of Zeus to last 100 turns before going obsolete (and that's probably a conservative estimate), and producing a free ancient cavalry every 5 turns that would get us 20 ancient cavalry. Hmm... 20 ancient cavalry at 50 shields each gives us... 1000 shields worth of units (!) for a wonder that costs only 200. The Pyramids and Sun Tzu's can match that in free buildings, but only on large pangea maps, and both require a much more significant investment of shields. To get the Pyramids, for example, you usually have to sacrifice or slow down your expansion. At half the cost, you can have a first ring city build the Statue of Zeus, and if you are the only one with ivory, you aren't even in a wonder race! I've seen Ancient Cavalry run over entire civs on smaller-sized maps without even breaking a sweat. Heaven help you if you get a leader and put these guys in an army.
Random luck factors determining who gets a massively overpowered wonder which spawns an elite Gallic swordsman every 5 turns? That's another "addition" to the game which I can do without."
CCM is an entirely different matter, entirely!