You only lose on the core licensing if you have more than 16 cores on two processors or you have 1 processor wiht less than 16 cores.
1 processor with 16 cores = 1 16 core server license
1 processor with 12 cores = 1 16 core server license
1 processor with 8 cores = 1 16 core server license
2 processors with 8 cores = 1 16 core server license
2 processors with 12 cores = 1 16 core server license + 4 2 core server license packs
Microsoft designed it around the most common system being sold. Intel Xeon dual proc 8 core systems.
