Yes you can try any values. But this does not affect the distribution of income among the miners.
I have more shares with less difficulty = get more coins.
If you put the stratum very high complexity from you for a long time does not arrive at all solutions, so your income may decrease. With a strong underestimation of complexity, you will not get more income than with average complexity. In the admin panel, I see how the income of the miners is distributed, which have the same power, but the complexity is different. Their income is the same.
Set the complexity within the current algorithm for this.
diff from 10 to 30