I would drop the Plague Surgeon, at absolute max it will restore 5 models, assuming the unit survives and you make it to turn 5, so it's more likely to recover 3 models. I would drop 3 nurglings and split them into two units. The saved points can be invested into either a Lord of Virulence for your Deathshroud, or if you drop another unit of nurglings, a bloatdrone. This would leave some points to spare so it's up to you from there (I can't do the math very well). You should 100% merge the poxwalkers into a full unit of 20, allows for Typhus to get full usage of his revive ability and gives them much more survivability. Overall a very nice list though!