Sue assumes two fellows in charge to be enough (7)
I believe the answer is:
suffice
'be enough' is the definition.
(I've seen this before)
'sue assumes two fellows in charge' is the wordplay.
'assumes' is an insertion indicator.
'two fellows' becomes 'ff'.
'in charge' becomes 'ic'.
'ff'+'ic'='ffic'
'sue' placed around 'ffic' is 'SUFFICE'.
'to' is the link.
(Other definitions for suffice that I've seen before include "Be enough" , "Be adequate" , "Serve - do" .)