Food from a Scalia (120) is only about twice that of an Arthron (55 or so). It’s certainly not worth the time to capture them (400 stun vs around 20 stun). The new food values are much better compared to their volume, except for the Scalia. Those thing are huge! The old 500 value seems right.
Perhaps, but the stuff that you is actually edible inside under all there armour probably isn’t that much. I suppose like cracking a crab open?