For anyone who gets the error of an "index being outside of bounds of array" upon launching on the SaveParser.exe a possible fix is to navigate to the SaveParser folder and opening SaveParser.ini with notepad and then changing

gamePath_W2 =(space)*the game folder directory*
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for example
gamePath_W2 = C:\Games\Total War WARHAMMER II The Queen and The Crone
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save the file and then run the SaveParser.exe proceed to change the army limit and click the lil button "max units in an army". Lastly, just remember to click on FILE (top left) and then save savegame in the actual SaveParser. DONE!