Outsiders in tiny company working with first of several magnates (7)
I believe the answer is:
tycoons
'magnates' is the definition.
('tycoon' can be a synonym of 'magnate')
'outsiders in tiny company working with first of several' is the wordplay.
'outsiders in' suggests removing the centre.
'company' becomes 'co' (abbreviation).
'working' becomes 'on' (on can mean working or activated).
'with' means one lot of letters go next to another.
'first of several' becomes 's' (1st letter of 'several').
'tiny' with its middle taken out is 'ty'.
'ty'+'co'+'on'+'s'='TYCOONS'
(Other definitions for tycoons that I've seen before include "Powerful businessmen" , "Very wealthy or powerful business people" , "Business magnates" .)