Some comments
"Some within ESA had expressed a little disquiet about the latter in conversation with El Reg recently, wishing that perhaps the agency could have been a little braver and pushed ahead with more exotic tech while leaving traditional rocketry with the commercial launch providers."
I have to presume the "little disquieted" were British and I will have to presume that if Britain happened to have any sort of launch providers they would eagerly support them or, are we confronted with the mindset that destroyed large parts of British industry like the car manufacturing that went from number two to number thirteen in the world.
On Ariane:
"The European Space Agency (ESA) charged the EADS subsidiary Astrium, presently Airbus Defence and Space, with the development of all Ariane launchers and of the testing facilities, while Arianespace, a 32.5% CNES (French government space agency) commercial subsidiary created in 1980, handles production, operations and marketing. Arianespace launches Ariane rockets from the Guiana Space Centre at Kourou in French Guiana".
https://en.wikipedia.org/wiki/Ariane_(rocket_family)
And on ESA and the EU:
"The political perspective of the European Union (EU) was to make ESA an agency of the EU by 2014,[79] although this date was not met. The EU is already the largest single donor to ESA's budget and non-ESA EU states are observers at ESA.....
ESA is funded from annual contributions by national governments as well as from an annual contribution by the European Union (EU)"
https://en.wikipedia.org/wiki/European_Space_Agency
Better keep the control where the money is.