Hey technological idiot. Please stop writing about things you do not understand. Because some n00bs might believe you.

Decreasing the block period, does nothing to decrease the propagation delay for any particular block size. Since the orphan rate is function of both propagation delay and block period, it is wash in terms of one must use smaller block sizes at lower block periods, in order to have the same resistance to centralization of mining (due to the economies-of-scale around winning your own blocks more often, thus avoiding the lost hashrate on orphans and waiting for propagation).