Some ideas: raiding, seiging, spell AI and more..

[Alneyan]

My main concern on the matter of clams is the impact of their removal (or at least, their nerfing) on the nations for which clams are the saving grace. For example, while Arcoscephale or Pythium are likely good enough without clams, what about T'ien Ch'i? The Celestial Empire isn't exactly regarded as being the most powerful nation around, and reducing their access to clams will probably have a negative consequence on them.

It would be even worse for Spring and Autumn T'ien Ch'i, and possibly other nations/themes (R'lyeh? Atlantis? Pythium Serpent Cult? I am not a scholar on these). Magic sites remain a solution, but T'ien Ch'i is probably not among the nations with the means to lead the expansion race on its own, and its jack-of-all-trade mages are almost begging for these hefty items boosting their magic paths; since such items are quite expensive, clams are more than welcome here. And of course, Astral pearls provide these versatile mages with a more varied source of gems through alchemy; it isn't so good to have access to all the magic paths if you do not have a steady income to actually use all your nice spells.