ok why are the spare modules not in the case (other than obvious space issues)?
I generally follow the layout of an arp 2600, but with utilities spread all over.. where they make sense...
so sound sources (& any inputs), filters, modulation, effects, control, final output mixing...
start top left, finish bottom right... this works for me in my main audio cases... I basically have sound sources on the top row, modulation on the next row down (with some filters etc to the right), filters on the next row down, percussion next row (waveshapers, logic etc to right), sequencing to the left on 2 rows and on the right effects above end of chain mixer
another way to look at it is to group by voices... starting at the left with oscillators, but you generally still end up with sequencing (control) at bottom left and end of chain mixer at bottom right... if of course you have an end of chain mixer, which it doesn't look like
if you have the top mantis vertical and the bottom one horizontal I'd move the data to the top case... same with the squid salmple...
I don't like having spare modules lieing about - I'd much rather have some blind panels in the cases - so I'd be buying another case about now and trying to work out how to join 3 mantises together... I'm sure there are some ideas in the mantis thread on modwiggler... this may actually help your issue too... some space between modules can help with workflow...
"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