Loving this so far!
And have say that Rhino Beetles and Stag Beetles are
excellent prototype inspirations, though it depends on how you want to go with the army - Is it primarily close quarters fighting with support firepower, or can it adapt to full combined arms, or some compromise between the two? That decision will make whether you have large "vehicle" sized items quite important.
Also, these creatures have
not developed from insects, I infer, so the other arthropods are there for inspiration as well - Chelicerates ( Spiders and scorpions, ticks and horseshoe crabs), the Crustacea ( Lobster, crabs, isopods and shrimps ), Trilobites and the rest of the Uniramians ( Apart from insects, the millipedes and centipedes ) - plus the more chordate features of the design ( Mammalia or reptilia is seems to me ). Possibly, though tentacles are a cliche and not
entirely justifiable on land dwelling organisms, you could look at some mollusca and even the Echinodernata ( Starfish, sand dollars, crinoids, sea urchins, sea cucumbers and brittle stars ) - particularly the "jaws" of the sea urchins, the terrifying Aristotle's Lantern
. . . Well, I'm letting my biology geek/science degree flag fly here today, aren't I?
