Could someone tell me how compatible the L5R 4th Edition is with the 1st Edition source books? I have the entire 1st edition (every book they released) and am planning on dusting them off to run a campaign, but would like to use the 4th edition rules. Will I find the 4th edition changes all my NPC stats in the 1st edition books I have? If it is going to take a massive effort I will just stick with my 1st edition material.