First, i've gotta say that there could be some points already said by other people. you said physics would work same as real world? then where could be no L points. since there are two moons, the L point will be unstable as time passes. It's really easy to caculate L point between two points, but between three points would be almost impossible. Now, let's make this problem little bit easier. if minmus diapeares, the L point will have same position with Earth-Moon L point. since all gravitational forces are same in KSP with real world(Kerbin's g = Earth's g, Mun's g = Moon's g), physical caculation will be exactly same. for sure, this work has some problems since radiuses are different. BUT, differences are so small that we can ignore that. I might have some problems with my thoughts, so tell me if you see any problems.