The spirit of the regulation is to have people with EASA licenses IF the aircraft is based in EASA Land. All countries are sovereign over their territory, as a consequence, IF you are paid for driving a plane, and that you are based in EASA, THEN you need an EASA License, ELSE you are not in the scope of law.
What a load of tosh! Why do you keep referring to the word "base" when it does not appear in the legislative text? Concentrate on the facts which concern the operator and the principle place of business of the operator. It has nothing to do with where pilots are based either, or are you suggesting that all those who drive planes for AA, and who may be based in the UK, need to get EASA licences?