[tinkthank]

Seems that in order to get lots of clams and have them be useful (that is, not get them first at turn 90), you need to
- produces water mages
- use those water mages to go and find water gems
- use those water mages to forge clams/turn
- use those water gems to forge clams

That is what you spend. This has a nice payback, of course.
People who do not horde clams can, surely, do other worthwhile things with those resources instead of produce mages, have them find water gems, have them forge clams?
This is not to say that Clams might be harder to research, or require 10-water 5-astral pearls to make (my personal choice), but they certainly do not break the game in my opinion.
I find the comparison to Warcraft III extremely poor, no offense intended. WIII is an excellent game for what it is, but lacks the diversity found in Dom2. I really dont think there is any "cheese" in Dom2, which is not to say that everything is perfectly balanced (I feel some nations are stronger than others on the whole, but that is just me), just that there is no real comparison to WIII ("when you get to 2 minutes 40 seconds you will have your Beastmaster do XXX while your opponent still needs 20 seconds to get that Grunt out...").
Any nation with good magic gem income capabilities just needs to fight those other nations to a standstill. Yes. But I just think that is easier said than done.
Just my opinion, however, and I am a certified newbie.