I've been reading a lot about Cyberpunk 2020 and Shadowrun, mostly 4&5e for Shadowrun. What I notice is there are large standing armies in Cyberpunk 2020, but in Shadowrun I only see "Security Response Teams" field mostly by Knight Errant or LoneStar. I'm aware that other groups in Shadowrun have inhouse security, but I don't see it very often. I also know about "MET 2000", but that's a standing army for hire, it's not in-house for any of the MegaCorps.
I'm aware about "War!" from 4E shadowrun, but reading over about SovOil, Petrochem, and the others it seems like every MegaCorp has a serious standing army. SovOil has one of the most impressive militaries I've seen so far, with military training, order, uniforms, and weapons.
Why is there a difference between the two settings?
Is war less practical in Shadowrun due to it's era?
Do states have more control over the use of mass conventional violence?
Was it just how the writers made the systems or settings?