The write up on the Chindits mentions they used WS 21 for platoon to platoon communications. This scenario seems to me to be rather unlikely but anything is possible, the set was not ideal for lugging around on patrols , being heavy and really it was a Brigade level set , not meant for that type of platoon level situation . From what I have read, the set was a bit of a flop in its intended Brigade level role anyway. These sets are to be found in N.Z. for some reason, never seen one here in Aust.
https://www.radiomuseum.org/r/mil_gb..._set_no21.html