Just moving the conversation to discussions for focus and ease of access should the mod balloon with comments.

So going with the idea that all three insectoids were tamable, and are tuned to better suit such with greater tamability and more fleshed out capabilities alongside potentially all having armour; what, then, differentiates them best?


The megaspider itself has a lot going for it already with its sheer damage and durability, and being a pack animal suits its size. However, full trainability might be a bit too much for it, even if it has near maximum wildness; maybe a trainability level below one that would suit it better? Given its nature as the upper caste, it doesn't really need to produce anything; it's more the guard than the worker proper.

The megascarab by contrast is a eusocial worker drone, being (just barely) the fastest insectoid, but also the least powerful one. It's described as a creature of utility, so then why not make it so? An insect dog, in a sense; a periodic nuzzle, moderate wildness, and the trainability to be able to rescue and haul but without the ability to function as a pack animal. Note that megascarabs are explicitly stated as not being able to reproduce individually, so perhaps they could be the product of spelopede or megaspider egg batches?

The spelopede then is the middleground in capabilities; thus, why not aim for something in the middle of the two? Leave the pure overwhelming power to the megaspider, the rescue and hauling to the megascarab, but still be able to function as a pack animal. Given its nature as the middle caste, perhaps let it rarely produce low amounts of insect jelly?