Thread Scarlett 18i20 and 48-point patchbay

I am using a Focusrite Scarlett 18i20 connected to a Focusrite Octopre, giving me 16 in's/out's in a Windows 10 environment. I recently acquired five 500 series mic preamps ((2) Neve 1073's; (2) Great River pre's); and (1) A-Design pre) racked in a lunchbox along with a hardware compressor. I also acquired a 48-point 1/4 inch patchbay. I use an XLR snake for the vocalists, guitarists, drum mics, etc. to plug into for recording. The XLR snake cables run from the recording room and are plugged in to the various inputs of the 18i20 and the Octopre to use via ADAT. I've been reading and studying various methods of hooking up my patchbay, but can't seem to get my head wrapped around some issues.

I would like to be able to patch some of the mic in's on the Scarlett and/or the Octopre to various outboard preamps and/or the compressor. The pre's are plugged in to the patchbay matching each of their in's and out's respectively. The hookup of the Scarlett and Octopre to the patchbay, though, has got me stumped.

Here's my specific questions:

1. For instance, mic 1 is a vocal mic coming in. I want it to go into the 18i20 input 3. Question: Do I plug the mic into input 3 on the Scarlett and then plug Scarlett output 3 into an out on the patchbay?

2. Does the above connection then allow me to patch from the output on the patchbay to the input on, say, the Neve pre, and then the out from the Neve pre back into the patchbay in for the Scarlett input 3? In other words, since nothing is physically plugged between the Scarlett input and the patchbay corresponding input, will this still work?

Sorry this is so convoluted. Maybe I should just ditch the patchbay and use Mix Control to make the patches?

Any insight would be appreciated.