Ah, Novgorod is a good example there. I just loaded up the save -- it can get all the way up to 39 shields if I tweak the citizen assignments -- not enough to change your analysis. That's a good site to switch to units right away. Yekaterinburg is harder to tell. We can switch to Whippet immediately without wastage. 28spt with its current configuration (dropping to 16 post-GA, I think, ignoring growth). Finishing the Factory gets us over 20spt post-GA. In all fairness, it's probably better to finish the Whippet, but it's useful to look at IMO. Then you have cities like Salonika or Samaria -- switching to another build wastes some shields. I'd rather complete the builds than waste those shields. Then you have cases like Antalya -- building a Power Plant with no shields in the bin. Yep, switch that to a military unit right now. I did set most of the "filler" cities I built to settlers. It's probably time to do the same with new captures (like Teayo or Tepetlaoxtoc -- even Admin Centers and Forges will take too long to pay off if we're <50 turns from victory).