This is a lot of thread drift, but sure, of course an arranger can be used that way.
In fact, one of my favorite combinations I've been playing with this year is a Nord Stage 4 with a Korg PA1000. Nord wins on piano, organ, VA synth, easy incorporation of custom samples, speed of assembling patches, MIDI functionality (controlling or being partially controlled by other boards), and real-time interactivity (i.e. the morphs and all the real-time front panel control). Korg wins on the non-piano/organ/synth sounds (i.e. emulations of other acoustic instruments), including having the kinds of articulations you're talking about, and it has touchscreen patch navigation (including search and set list functions), and good rhythm programs, which I use on my duo/trio gigs that don't include a live drummer. It does have a drawback in that its workflow, front panel layout, and manual are all centered on an arranger orientation I don't really use, so it can take some extra effort and "re-thinking" to use it the way I need. (Also, I would have preferred the PA4X with its better action, full set of sliders, assignable outs, better screen... but it crossed my "too heavy" threshold.)
When I don't need the drum accompaniment, I'm more likely to take my MODX7. It's lighter weight, 76 keys, with a better workflow/interface (for my purposes), and is more versatile in other ways... but I do miss the aftertouch and some of the sounds of the Korg. The new MODX M looks even nicer, with a lot of additional front panel control, better seamless sound switching (up to 6 parts instead of 4), improved split management, and (coming in January) improved scene functionality and a full VST implementation as well. All that even before you get to any of the sonic enhancements. (Some of which actually make it more Nord-competitive... VA synth engine, updated pianos/EPs, better rotary effect.) Though you're presumably already familiar with all of this from your Montage M experience.
Bottom line: There are multiple ways to accomplish one's goals, with different trade-offs. Use whatever works for you.

