How blocks dispatch to SM

Kernel has 324 blocks and the number of resident blocks per SM is 3 for this kernel;
Waves for this kernel is 1 and every 3 blocks should be sync.
How these blocks dispatch to sm?
0, 1, 2 dispatch to sm0? or 0, 108, 216 dispatch to sm0?

Is it better when 0, 1, 2 dispatch to sm0 due to these block sync?

It is not specified. It can be any arbitrary order.