if your 2nd 'skiff' is the same size you'd be better off with a Mantis - more space as no rack wart, better power and probably cheaper too!
as for this skiff - too many sound sources not enough modulation - for this many voices I would want a case twice the size - more modulation, more filters (one for each vco), more vcas and just more utilities in general
consider mutable veils to eke another 2hp out of it too, you'd also probably be better of with plaits over the micro clone of it's discontinued forebear
I would consider sharing skiff 2 as well - module recommendations are probably best based on the whole thing - mixing and midi->cv - rather than just half the intended rack
to get more variety out of a modular I think (at leasst loosely):
sound sources < sound modifiers < modulation sources < utilities
is a significantly better idea than anything else
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities