I just learned:
as the block length varies, the number of submitted shares will too vary, and thus is not directly correlated to the payout value.
At constant c/m payout will be more or less the same while submitted shares for a block are fluctuating (for all of us BTW).
So this explains why submitted share number seems not to be related to payout.
BTW: since yesterday pool hashrate (only considering top 100 miners) went up from 150K c/m to 350K c/m
This is gaining momentum !!! ;-)