I presume the squads 3 and 4 of PBs are DSing in on the icons? All well and good, just... beware enemy templates and blasts the turn they come in, since you can't run, so are so-tightly clustered. Nurgle forbids they have a Thunderfire Cannon.
I agree with Ryu, larger blocks of Plaguebearers are better and Plague Drones are a better delivery system for getting upfield. You don't need to pay the Herald tax to get them FNP as many times with fewer, larger squads for one, freeing up a good number of points for, say, Mastery Levels. Or Plague Drones.
What sphinx of plascrete and adamantium bashed open their skulls and ate up their brains and imagination? Imperator! Imperator!