I’m sorry but it was by no means unique for OCs of independent or detached subunits to hold powers of CO under AA 1955 (note
@Danny_Dravot, I was clear in my previous post that this was pre-AFA). And when the OC was absent, command was handed over to the 2ic who assumed the powers IIRC unlimited by rank.
It was actually quite common for Engineer Squadron OCs to have powers of a CO. There were at least six Independent Squadrons where the OC reported directly to the Brigade (or equivalent) Commander and there was no RHQ in between. Those Squadrons never had an admin relationship with any of the major units it the Brigade. They were stand-alone, with their own UIN etc etc. As an example, OC 59 Independent Commando Squadron had no command or admin relationship with the other Army units in the pre-SDR 3 Commando Brigade. His soldiers did not go in front of CO Cdo Log Regt; the OC dealt with them with powers of CO derived from AA1955.
The Field Squadrons in UKLF Engineer Regiments were similar; able to operate independently of RHQ when deployed, routinely on long roulement tours like a Belize or the Falklands. Quite how a CO in the UK with no command relationship in theatre could deal with an offence that occurred in theatre beats me.
These powers were not delegated; they arose directly from AA1955 (of which you presumably have no experience). Your statement about “senior subordinate commander” is entirely irrelevant as no there was no such thing in the Army.
I can think of several cases where OCs with power of command dealt dealt with tanks that only a CO could deal with and awarded punishments only available to a CO. Example; an OC who dealt with a SNCO for negligence regarding explosives handling and awarded a Severe Reprimand.