No surprise that you grok'ed it, you seem to have a solid foundation!

In this setup, you can use both Maths and the Disting as FM modulators, each can do both audio rate oscillation and LFOs. For random, you'd want to use the Disting here as it has a couple random algorithms.

One final note, you also get a Precision Adder in Links, so thankfully you can use the Disting for other things.

See below for an overview of Maths, and another for Disting though they've added more algorithms since this one was made: