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

[Boron]

Soapyfrog said:
The point is that while there are optimizations, they dont invalidate other strategies in the way that, say, soul contracts do. You cant compete with a soul contract in terms of regular units with any other blood summons. At least in the other arenas, the optimizations are not so blindingly obvious...

Well storm demons beat the devils . A SC beats them too etc. etc. .
So soul contract hoarding doesn't ensure you a win .

With clams etc. it is the same though not so severe :
If you only convert your water gems to clams then you don't lose too much but then it is a rather slow process .

If you convert back your gained astral pearls to speedup the clamhoarding process though then you lack them for some time and are vulnerable until you start to use them .
And there are too many factors to evaluate if your clamhoarding is good enough . If the other player intead gets 1 province more as you every 1-2 turns while you get 2-3 clams more the other player has still an advantage over you because he gets more gold , gems from sites , perhaps freespawns etc. .

I thought exactly like you do a few weeks before but i think now that hoarding is not a no-brainer .