the answer is yes...
both are valid options
personally I went for adding what I though was missing - and rearranging over time so that I have a more structured system - something vaguely like the layout of a 2600 - although at the moment I have a subset in the living room which I use - 3 cases (2 for audio and 1 for video) - I may shift this round soon
currently I'm at 8 cases approx 1800hp - with maybe 300hp free spread throughout - some of which is diy backlog (which I should really get round to)
but saying that I know of lots of people who set up each case as an individual instrument...
basically what works for you works for you...
"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