Changing the direct files doesn't generally work.
1) Because the game uses these compiled versions like Core.bin and the files you see are for reference half the time.
2) Because Steam validation can occur.
So you have to use a mod and you only need to alter one file GlobalDefs ... but you have to use the right version which I believe is in Retribution's folder in the game directory. Copy that to a "MyMod/Game" folder within your MyDocuments GC3Crusade directory and you should be able to get this working.