ChickenHouse
What you describe may be the way it is in your little corner of Europe but it is not the norm and nor is it compliant with the EU Regulation. For example:
FCL.210 Training course
Applicants for a BPL, SPL or PPL shall complete a training course at an ATO. The course shall include theoretical knowledge and flight instruction appropriate to the privileges given
There is no separation between the theoretical knowledge and the flight training, they are both elements of a single course of training. An ATO may elect to provide the theoretical knowledge training itself or to sub-contract to another training provider. In either case, it is the ATO's decision and not the student's as it is the ATO that is responsible for the training course. The exception is where an ATO is approved to provide flight training only and, in this case, it becomes the student's responsibility to find another ATO to provide the theoretical knowledge instruction.
FCL.025 Theoretical knowledge examinations for the issue of licences and ratings
Theoretical knowledge examinations for the issue of licences and ratings
Applicants shall only take the theoretical knowledge examination when recommended by the approved training organisation (ATO) responsible for the training, once they have completed the appropriate elements of the training course of theoretical knowledge instruction to a satisfactory standard.
It is not simply a matter of the ATO certifying that the training is complete, it must also certify that a satisfactory standard has been reached and must recommend the candidate to sit the exam - it is not the candidate's choice.
By the same token, it is not simply a matter of building the flying hours and applying for the licence. The ATO that is conducting the course of training must recommend the candidate for the skill test, which means that he must first satisfy that ATO that he has achieved a suitable standard.
FCL.020 Student pilot
A student pilot shall not fly solo unless authorised to do so and supervised by a flight instructor
What is this if not a requirement to be "signed off for solo"? Training must be conducted within an ATO and so it is the organisation's approved procedures that determine the exact requirements for solo authorisation.