Thank you very much. I actually found the topic you linked but it was either too late or I was too dumb to read correctly what is written there. I was trying to find UpdateDatabase inside file Expansion1_Expansion2.xml, which of course isn't there. What is interesting it fixed my problem partially - the statue of liberty works correctly, however unique units still do not require strategic resources(I didn't mention this problem in previous post as I thought it is one and the same problem where game uses mechanics from previous expansion). I will fiddle a little bit more with load order, perhaps problem lies in choosing right priority to mesh with these mods or it is problem with some other file loading at wrong time. Either way, thanks for help, it seems I am on right track once again.
Edit: checking more, it seems only polish hussar is broken, while other unique units are fine, seems likely that mod itself is breaking something