Great Greek warrior has top fighter pilots surrounding Ernestine (8)
I believe the answer is:
achilles
'great greek warrior' is the definition.
'achilles' can be an answer for 'warrior' (I've seen this before). I'm not certain of the 'great greek' bit.
'top fighter pilots surrounding ernestine' is the wordplay.
'top fighter pilots' becomes 'aces' (I've seen this in another clue).
'surrounding' means one lot of letters goes inside another.
'ernestine' becomes 'hill' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'aces' placed around 'hill' is 'ACHILLES'.
'has' acts as a link.
Can you help me to learn more?
(Other definitions for achilles that I've seen before include "Ancient soldier" , "Heroic Greek with damaged heel" , "Ancient Greek with weak heel" , "Legendary hero with weak spot" , "Famous Greek" .)