Sorry I didn’t reply to this sooner, things have been a bit … crazy.

Most of the innovation humanity has come up with is tactical, and in the use of mechs and battle suits. Human infantry simply aren’t really deployed much against anything but batarians, and unless they’re fighting the Fist or something, that means shitty Batarian State Arms weapons and armor — deadly to colonists and lightly armed militia but no match for even B-rate marines with decent leadership.

Battlesuits are a big part of the change up, as well as the use of DACT troops dropping behind enemy lines, kamikaze mech attacks, and using the bigger mechs as pressure units to deform enemy lines and hit from a different direction. Some infantry boarding tactics have evolved to a degree but much of this is still room-to-room clearing with shotguns and melee weapons (to keep from blowing holes in the hull…or the fuel system.)

Artillery is a tricky one — Elcor and volus are the big masters of artillery. Both Ahern and Florez (who wrote most of the current SA playbook) disliked static offensive points and felt that artillery was best fielded as highly mobile. There’s a MAKO conversion with the crew cab swapped to carry saturation missiles that’s about the closest the SA currently has to an artillery platform.

The armor the SA fields is dangerous because unlike salarian and asari armor, it is very numerous. Salarian and asari tanks are supremely powerful but very rare, while the humans (taking a queue from the turians) are beginning to deploy MAKOs with all infantry. Dedicated units like the GREAT WHITE are a good match up against almost all turian and the lighter asari armored vehicles — although superheavy krogan tanks would trash them, there aren’t many of those left.

I haven’t honestly decided what to do with Ash yet, aside from making her an Action Mom. I think ME3 tried to do the right thing but it would have made more sense if they had done so BEFORE ME3 — I’m not seeing why they would wait until the whole Reaper thing to even bother. I mean, the whole Spectre thing is about operating beyond the law to get things done, and when giant black deathrobots are eating everything who gives a shit about the law?

The change is simple: there are gradiations of armor for Non-N7 and N7 troops.

For example, the ‘stock’ N7 armor is Onyx armor, just like the stock SA Marine armor is called Onyx. But Onyx-N7 is much thicker, higher grade, with more built-in stuff and better systems.

Devastator armor was far too useful to be sidelined to a small number of troops, given that powered armor is a big force multiplier. In the Premiseverse the ‘stock’ N7 is assigned to all heavy weapons units. The N7 version of the Devastator has better actuators and the red haptic lighting to differentiate it from the stock version, as well as (again) thicker fields, omni-armor and the like.