The mods are like the author are temperamental and don't like their stuff to be encroached on and do not suffer ignorance long. Other mods will either crash or mix up items but it will give you a courteous .txt saying "these are the conflicts, here's what you can change them too" (What mod does that BTW? Forge?). Reika's mods slap you and say "NOPE" and they punish ignorance like a stern aged teacher lady with a steel rule and ample reason to use it(It's probably HSLA too).