The initial idea I put forward for him as a working example was that parasites would be trash-mobs, swarming players and individually stalking them when the situation permits. Accompanying them would be swarms of the infested, which would also be used for slave labor, and if any individuals were interesting enough, they'd be de-wormed for use as personal maids or something. These would be followed by actual Mishhuvurthyar themselves, but would basically be physically mature but very young, inexperienced individuals thrown into battle to prove their mettle by killing people bare-tentacled - they'd have to be clever and/or sneaky enough to move into closer range for melee AND survive to get promoted. It's absolutely vicious and also makes a point by showing just how powerful and dangerous even an unarmed one is. Serving as actual firepower and drawing most of the attention so that the former two have a chance would be Mishhuvurthyar Troopers; these are the ones that survived by proving themselves. Instead of PA, they're clad in mere un-powered suits with thick armor plating, a shield generator and thrusters; the weight, they are well able to lift themselves, and includes maybe any four guns they'd like to carry in addition to any attached to the suit itself. Very dangerous and more than a match for a single player. After that, I imagined that those that were very good at killing were allowed to grow into Crabs, which would follow the same theme and be used as fire support or even like AFVs. All depending on how large they've grown.
This is that bit about the 'Type' of Crab Arieg was talking about. It's not an actual subspecies, but a military occupation or role. A type of soldier. From there though, we'd go towards command; Mishhu fit for that may be granted a Ripper, leading to their dismemberment into a 'brain slave' that's grafted into the chassis. I always hated how ridiculously stupid and idiotic Rippers were when I read any plot. This would change that, and make them as dangerous as an Elite was to a squad of normal human marines in Halo's books; completely outclassing. This way, that
Hopeless picture suddenly makes sense. Hybrids, I suggested play specialist roles though, where they're primarily logistics and administration (you now see one with glasses sitting at the secretary's desk) or serving as scouts, snipers and infiltrators/intelligence. Given that they came from older Neko stock, I reasoned that they'd have enough Hemosynth Ability to wrap all their tentacles up and bind them in a thin, fleshy sheath or something. Nightmares would serve in the same capacity. However, the Hybrids would be more prone to being logistics and administration, while Nightmares would be more prone to take specialized field duties. This reduces the amount of humanity players see in the Mishhu military by putting them in more uncommon roles.