It's a doctrine thing. Yu Jing could have their soldiers ride cows into battle. But they don't, because they decided their resources are (very cleverly) better used elsewhere. The same applies for embedded Infowar experts. We know Yu Jing is very good at Hacking... They utilize data manipulation all over the place. But that doesn't mean they hand those guys a firearm and shuttle them to combat hotspots. Nomads do that though, because it works with their doctrine and approach to warfare. Yu Jing just favors other approaches.
Nomads are also a society which is basically founded on the idea of keeping a secret data network isolated and protected from a massive interplanetary AI with access to billions of computational nodes. Their existence is predicated on having the best hackers and hacking technology in the Sphere, and even then only the best of their best gets access to the HD+ as equipment. The only other troops that do are AI aspect designed specifically for it, and Alien elite cyber-combatants. To use a HD+ you need to be on that level and I genuinely don't think that outside of those factions anyone is, not to the extent of being able to deploy them as a military unit.
Out of all the factions only 3 have access to a HD+. Nomads, Aleph, and CA. Even the hyperpower doesn't have any units with a HD+.
In all fairness, I'm quite sure the Nomads are doing the same; the Data Vault the Interventors use is supposed to takes up most of the central portion of Tunguska due to the massive amounts of sheer computing power required for its storage and security, and I read somewhere that the Observance are responsible for the security of Arachne and have a mountain of computing power themselves. The only other military unit with a good excuse to have access to such an expensive set of infrastructure that doesn't already is the Hassassin Barids. This is working off the assumption that what makes a HD+ work is massive amounts of offsite computing, is there any information on the construction and operation of the various Hacking Devices anywhere?
From a setting perspective, the only Hacking Devices drawing on off-world resources are the EVOs. Everything else is Comlog + Hacking Device + Hacker Skill.
Ironically, this probably means that for sheer hacking power the Fusiliers or Zhanshi could take down the Nomads by themselves just thanks to numbers and spare bodies. Who'd have thought that the most formidable hacking threat in the Sphere shared a WIP value with the Trauma-Doc who can't tell a medikit from a pistol 40% of the time?
@SpectralOwl That's probably pretty accurate. Remember that the Nomad nation is orders of magnitude smaller than YJ or PanO. So for the Nomads, their limiting factor to their infowar capabilities is the number of competent hackers they have. These hackers are admittedly very good, but they don't have too many of them. This means they can afford to give the very best that pricey HD+ tho. Whereas PanO and YJ don't have the manpower issue, so they just have regular HD after regular HD and just have a bajillion hackers.
