Both players are very good.
Like that is something you don't know...
Sometimes a player steps up...like Diow last year.
Be it circumstance, talent, or the particular role a player falls into, makes all the difference in fantasy basketball.
As stated, Harrington is the best bet right now.
But is Diow a one time flash in the pan?
I think not.
His value as a multi-purpose player will prove paramount if one is patient enough to stick with him.
It is hard to stick with players when you search the waiver wires and find those players that "seem" to have stepped up. We are all searching for the sleeper of the year.
The hardest part of fantasy basketball is to not panic when the proven players falter and to stick with them even if you have to put them on the bench for a while.
Harrington is a keeper. But do not dismiss Diow too soon.
Sorry, this does not answer your pertinent question, but I did want you think about this for a long term assesment.