So far, I've populated a Happy ending skiff with a pre-amp, a sample player and the main workhorses which are an Instruo Lubadh and an Arbhar and wondering what the community would subtract/add? I know some of this is purely subjective, but I'm just trying to get the most bang for the buck
Love the direction you're going based on what you describe! I'm no expert, only a half-year into modular myself, but a couple things that popped into my head right off the top:
If you want the most bang for your buck, Instruo probably isn't the way to go. Granted, those modules seem really cool, I'd love a Lubadh myself, but I'm all but certain you can replicate what you want to do with those modules with much less expensive options, and probably save a little HP in the process.
Same kinda goes for WMD, though I can understand why SCLPL would have particular appeal for your purposes.
You're going to want some VCAs (at least something like a Doepfer A-135-2, or an A-130-8) and some mixers. And some multiples, preferably buffered multiples. I imagine the ES can do some of these things, but you'll want dedicated jacks/units too. It also wouldn't surprise me if you end up wanting more ADSRs.
I might try my hand at building a skiff I'd go with for what you describe just for fun!