Great supplies at the front packed by soldiers into two cases for your compiler (7)
I believe the answer is:
immense
'great' is the definition.
(immense can mean great or huge)
'at the front packed by soldiers into two cases for your compiler' is the wordplay.
I cannot really see how this works, but
'soldiers' could be 'men' (men can mean a group of soldiers) and 'men' is found in the answer.
'compiler' could be 'i' (the person who is writing these clues) and 'i' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
'supplies' acts as a link.
Can you help me to learn more?
(Other definitions for immense that I've seen before include "Very big, exceedingly great" , "Jumbo" , "'Gigantic, extensive (7)'" , "'Vast, colossal (7)'" , "Huge, considerable" .)