Hi there
I am fairly new to all the world war research and stuff, so this is just a guess in answer to your question based on the very few details I know regarding my Grandad.
My dad has told me that my Grandad fought with the 8th Army in North Africa..he fought at El Alamein, then went on to Burma...where my dad has told me that Grandad fought as a chindit and with the 'forgotten army' (the 14th army).
Maybe this is how your Dad fought and the 8th Army that you mention is from when he fought maybe in North Africa?
Please dont shoot me down people in the know if I am wrong

...I am just putting things that I have been told by my Dad and passed down info is not always gospel.
Anyway hope this helps you.