You can have that.
It's barking mad, but you can have it if you want.
Just some rough calculations, I did this in a hurry so there could easily be a mistake, but:
Putting 4 sockets on the side walls, individual breakers
2 metres T&E from CU to garage four ways --> 8m
Socket 1, drop of 2m from entry into garage --> 2m
Socket 2, across the ceiling 4m, drop of 2m --> 6m
Socket 3, along the wall 2m, drop 2m --> 4m
Socket 4, along the wall 2m, across ceiling 4m, drop 2m --> 8m total
Grand total of 28m
Putting 4 sockets on the side walls, ring circuit
2 metres T&E from CU to garage two ways --> 4m
Socket 1, drop of 2m, rise of 2m --> 4m
Socket 2, across the ceiling 4m, drop of 2m, rise of 2m --> 8m
Socket 4, along the wall 2m, drop 2m, rise 2m --> 6m
Socket 3,across ceiling 4m, drop 2, rise 2m --> 8m
Return: 2m along garage wall to close the ring --> 2m
Grand total of 32m
Costing:
T&E assumed 60p metre, £3 per breaker module, it doesn't look like there's a big difference in price between a 12-way CU and an 8-way so I'll ignore that and assume it's dwarfed by the overall price for the CU replacement.
Part cost for ring:
1 breaker: £3
32m T&E: £20
Total £23
Part cost for individual circuits:
4 breaker: £12
28m T&E: £17
Total £29
I just paid £6 for a HUGE increase in the flexibility of my socket arrangement, and that's mad?
I'll leave you to tell me the catch, as I'm sure you will