The Group concept among the Elements allows you to link their behavior. In an AWM2 (sampled-based) Part each of the 8 potential Elements is a complete synth; complete with its own oscillator, filter, amplitude generator, LFO, volume, panning, etc., etc., even its own routing to the Insertion Effects blocks.

Expanded Articulation Control = Element Behavior
When the XA Control (MONTAGE’s programmable version of ‘Super Articulation’) is applied you may find it useful to have Elements linked in groups… Elements in the same Groups will be selected together… particularly useful for the “Cycle” and “Random” articulation functions.

From the “Mastering MONTAGE” Article series… (link provided below)

“The XA CONTROL is designed to be musically invisible. It is the way that different articulations can be recalled instantaneously and smoothly "knitted" into the sound you are performing. These functions are assigned on a per AWM2 Element basis include: Normal, Legato, Key Off, Cycle*, Random*, Assign Switch Off, Assign Switch 1 On, Assign Switch 2 On.

*Random - the Element behavior is like Cycle but this time the Elements within the Group will be selected randomly rather than in numerical order.”

__ If all Elements are set to “XA Control” = Normal, for example, they will all sound together if the Note and Velocity Ranges match.
__ But if all Elements are to “XA Control” = Cycle, and are in the same Group, only one of them will sound at a time… thus creating a cycle of sound… for each note-on the next Element will be called to sound.
__ If you place four Elements in Group 1 and the other four Elements in Group 2 you will have a situation where one from each Group will sound with each note-on event… each Group will cycle, Group 1 — 1-2-3-4… while Group 2 — 5-6-7-8…

Extra Credit:
Mastering MONTAGE #13: Assign Switches 1&2