Compare the formation processes of igneous, sedimentary, and metamorphic rocks. In general, which process can be the most direct, requiring the fewest number of steps? Which can be the most complex?

I am guessing igneous rocks are the easiest because the formation process because the magma cooling is either felsic or mafic magma and intrusive or extrusive which characteristic give the rock families. The most complex would be sedimentary rocks because they can have much more steps considering the way limestone formation is when it's is either chemical or organically formed.