Scholarly rankings of #SystemsThinkers may not line up with popularization.  Counting h-index is different from number of citations.  
https://coevolving.com/blogs/index.php/archive/citation-rankings-for-some-systems-thinkers/
You might be interested, @144mb, in the lineage of philosophy in systems thinking as American pragmatism from Russell Ackoff and West Churchman, back through Edgar A. Singer Jr. to William James, and then forward to Stephen C. Pepper and Eric Trist. In Appendix 1, starting page 38, at https://coevolving.com/commons/2024-01-sciencing-philosophizing-jisss