Looks interesting, although I'm not particularly familiar with the current
GW daemon range.
On the Spoilpox Scrivener -
Nurgle’s Grace (2)
This model has Command (1), and when issuing an order to a Nurgle Unit, lowers its suppression by 2 instead of 1.
This should either be Nurgle's Grace (1) or confer Command (2). Given that he appears to be the 'lesser' leader, I'm guessing it is Grace (1)...
On a quick read through, the lack of long range shooting and high pen weapons would certainly be a challenge, although the speed of the Plague Drones will help there. With the unit selection as is, I would be inclined to bump Plague Swords up to PEN5, and increase FOR on everything but the Prince by 1.
A unit of Warmachine Bile Thralls would be an easy way to add some more ranged attacks, and they would fit reasonably well with
GW's Nurgle range.