Perhaps hawkish duos lead on (7)
I believe the answer is:
forward
'on' is the definition.
(I've seen this in other clues)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for forward that I've seen before include "Footballer; ahead in time" , "Pushy - send (on)" , "left-winger, maybe" , "Attacker" , "going on" .)