Back in the early 2000s (around 2003 or so, I think), the Army decided that at the O-4 rank, officers could designate as "Ops" ie, basic branch, or into a Functional Area. Among those Functional Areas were Strategic Intel, FAO, Civil Affairs, something that dealt with nukes, the aforementioned Strategic Plans & Policy (now just Strategist).
One of the best descriptors I heard of such types was the acronym KOOKs - "Keepers of Odd Knowledge"
I was a 59 from 2008 until I retired in 2016. 3 years in the G-5 at the 82nd, 2 years in grad school (at A&M), and the last 3 years in the Joint & Army Concepts Division at ARCIC.
The guy you really want to talk to, OP, is COL Francis Park. He runs the Basic Strategic Arts Program (BSAP, aka 59 school) at Carlisle. He's extremely smart, knowledgeable on all things 59, and good people.