Speaking as a novice, the way you have drawn the circuit, it is a radial circuit with branches. The CB should be less than the lowest current carrying capacity of any of the cables. 2.5sqmm T+E cable is rated variously at 20A, 21A or 27A for typical installations. As long as it isn't de-rated by running through insulation, a 20A CB is typical for a radial circuit in 2.5sqmm. You can then have as many sockets and branches as you like as long as the floor area served is less than 50sqm.
32A is the largest capacity CB to serve 13A sockets. It is typical for a 2.5sqmm ring final circuit. These circuits can only have spurs serving single sockets or FCUs (although a single socket can be 'double gang' with two outlets).
Many of the electricians in this forum dislike ring final circuits and see them as a misguided post-war cludge. Originally, ring final circuits were rated at 100% more capacity than a radial circuit using semi-enclosed fuses. This has been reduced to only 60% more with circuit breakers but there is still a chance of overloading a conductor if the circuit is poorly designed. Except for kitchens, you can get more capacity by breaking a 32A ring final circuit into two 20A radial circuits on separate circuit breakers. This also removes the chance of overloading cables and allows you to have branches serving many sockets.
Remember, building regulations specify the worst practice you can get away with without risking prosecution. In contrast, 'best practice' changes much more slowly, generally only with new inventions.