I don't know the precise situation in other European countries, but the cabinet making process in Ireland and (I think) the UK is an absolute joke. Over a matter of a few hours the prime Minister designate calls in the favoured parliamentarians and tells them he is making them minister for such and such. The actual portfolio allocated may have no bearing on actual prior knowledge, experience, or stated preferences.  It often is explicitly not the brief the relevant parliamentarian covered in opposition - lest his/her statements in opposition might come to haunt him as Minister.  Sometimes some appointee has a hissy fit regarding their allocated portfolio and a hasty re-shuffle ensues.

The whole process ensures most ministers, however able, are almost complete novices in their newly allocated policy area and are the easy sitting ducks for experienced civil servants who have spent a lifetime in that area and who can easily browbeat their Minister into their preferred policy positions.  By the time the Minister becomes sufficiently proficient in a policy area to challenge his/her civil servants, they are reshuffled to a new portfolio...

And so the veneer of democracy is maintained whilst the real Government is carried out by career civil servants with very privileged pay and pensions provisions that are higher than in the rest of Europe.  Sometimes they even sabotage a Minister who is proving "difficult" with wrong, partial, or downright mis-information.  Because of the the archaic tradition that Ministers are responsible for everything that happens in their department, it is the Minister who must fall on his sword whilst the Civil servants smile in the background.  Not that there is much of a tradition of Irish Ministers falling on their swords no matter how egregrious their mistakes...

Index of Frank's Diaries