Ditto for maintenance
Recently due to compliance with EASA Norway found that there was no CAMO' s in the country for some classes of aircraft, in theory aircraft owners could contract in a CAMO from any EASA state.
The Norwegian authority's took the view that they would only let this work be contracted to CAMO's in some EASA states, as you might guess all of Scandinavia, Germany, The Netherlands, The UK and some others were on the list. I will leave you all to ponder who were not on the list !
To me this indicates that EASA is not a level plying field and those airworthiness authority's who wish to uphold high standards know who is and more importantly who is not up to scratch.