Commander of less sensitive unit (6,3)
I believe the answer is:
number one
'commander of less sensitive unit' is the definition.
The answer and definition can be both quantities as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'less sensitive unit' is the wordplay.
'less sensitive' becomes 'number' (numb means insensitive or unfeeling).
'unit' becomes 'one' (synonyms).
'number'+'one'='NUMBER ONE'
Can you help me to learn more?
(Other definitions for number one that I've seen before include "arch" , "Yours truly" , "officer on board?" , "it concerns egoists" , "the most important person" .)