First of all: 3*5 < 4*4

I couldn't see how could the primary goes lower, as making a vitae requires 4 grab of salt salt vitae mors, doing better than 4 arm 4c loop means there must be a multigrab and multidrop

A dedicated hexarm can easily feed all the outputs (with some clever trick of course), but hard to do anything else, so the multigrab must happens between salt and mors

The mors goes either disposal or a waste chain, and a 4c loop multigrab is a forced 1-length hexarm, which seems not able to process the mors with either way, not regarding the geometry issue

5c loop somehow works by tinkering the layout a lot, and this solve should have achieved min latency under 5c loop