Waste their Shops.
If you wasteland their workshop after they've dropped a sphere (even assuming they didn't drop any moxen 1st turn), you are really behind if they have another workshop. Other than both of you having drawn a card, its as if you're back on their first turn, but they just dropped their 3sphere for free.
I know if they go workshop 3sphere and you have a wasteland, then 90% of the time you will wasteland their shop, but if they drop shop #2....