That is part of the plan, not to write out an alg for every possible letter pair but for I think the 256 unique cases for adjacent face and opposite face comms. I don't think you even need a comms list for it to be honest, it boils down to the same few algorithms:
U r U' [l2] U r' U' [l2] - an M2 variant
r U2 r' [d2] r U2 r' [d2] - typical opposite face case
r U r' [d'] r U' r' [d] - typical adjacent face case.
f [u'] f' U' f f' U - solving last 2 centers on adjacent faces by cycling Ubl -> Ufl -> Ful
x' r U r' [d2] r U' r' [d2] x - " " " " on opposite faces by cycling Ufr -> Ubr -> Dfl
I set up to one of these cases when I can't see a 8-move comm straight away
Yea I know it is meant to be intuitive, just kinda wanna explore the concept by executing algs.
Edit: I've tried this algs, now I know what I'm missing. I've limited myself too much that I'd never explore the l2 slices. The M2 variant really helps a lot opening my understanding to the comms, so is the 2nd last one, now that I can see how pieces go in place. Thanks a lot Ollie, this does helps. Hopefully I'll be able to sub 6 consistently before 2013 make its call.