Soldiers also included in scheme (7)
I believe the answer is:
platoon
'soldiers' is the definition.
(I've seen this before)
'also included in scheme' is the wordplay.
'also' becomes 'too' (synonyms).
'included in' is an insertion indicator.
'scheme' becomes 'plan' (I've seen this before).
'too' placed into 'plan' is 'PLATOON'.
(Other definitions for platoon that I've seen before include "Division of company" , "Small military unit" , "Military squad" , "Small body of soldiers" , "part of company" .)