do I really need more than that?
No. Follow and assist is literally all you need for multi-boxing DPSers. I've never bought into the whole "have a macro for every spell" rubbish, and get along just fine.

If you add healers to the mix then more complex macros for flexible healing can REALLY pay off, but for what you're doing follow and assist will do fine.

Have fun, and well done for keeping it simple rather than letting yourself be over-awed by the whole thing.