easiest way to trigger modules

Simple idea, but after articles & tweakheadz links, I still can't wrap my head around it.

-Axiom 61 Mk.2 as main keyboard controller
-4 hardware modules with MIDI In and Out for each one
-For my modules' control knob (filter, modulation.) data sent out of their respective MIDI Outs, that would mean I'd need a MIDI Interface with a MIDI In for each device.
Example for the Moog Slim Phatty: (CC) messages are generated and transmitted on the MIDI Out connector

1) A device like the MOTU Micro 5x5 USB...4 In & Out MOTU Ports would be used for each of the 4 modules I have (Moog In->MOTU Port 1 Out....Moog Out->MOTU Port 1 In) and so on for the other 3 devices.

2) If you get a USB MIDI Keyboard controller like an Axiom 61 Mk.2, I suppose you'd need both it's USB connection to the computer & it's MIDI In/Out to the 5th MOTU Interface Port...

http://tweakheadz.com/how-to-get-started-with-midi-and-the-difference-between-midi-and-audio-is-explained-along-with-many-other-core-concepts-for-building-a-home-recording-studio/

In this tweakheadz link, about 80% of the way down, it says "Advanced MIDI In/Out/Thru Brain-Teasers"
and in the second small paragraph it says "Now if each synth was on a different PORT, would both synths make a sound. Nope! Why not? Each port is totally discrete, that is separate. The data on Port A does not go down Port B. To recap, remember, each port has 16 channels of its own. The Port is the parent; the channel is the child."

So if I had a 5x5 MOTU Interface, 4 modules on 4 different ports... would the Axiom on Port 5 be able or not be able to trigger a patch/midi channel on the other port devices? (assuming the other devices were setup on separate midi channels on their own)

I'm either misreading or overlooking something... I just don't understand. I'm trying.