Old male German paramilitaries overwhelmed by strength test (10)
I believe the answer is:
assessment
'test' is the definition.
(an assessment is a test or examination)
'old male german paramilitaries overwhelmed by strength' is the wordplay.
'old male german paramilitaries' becomes 'SS men' (members of the SS).
'overwhelmed by' means one lot of letters goes inside another (inserted letters get absorbed or overwhelmed).
'strength' becomes 'asset' (asset can mean a strength or valuable quality).
'ssmen' put into 'asset' is 'ASSESSMENT'.
(Other definitions for assessment that I've seen before include "Process of valuation" , "test" , "Judgement" , "Opinion" , "Evaluation, estimation" .)