Best way to play C'tis Miasma?

[Zooko]

In my experience Empoisoners casting Summon Skeleton only win about 80% of the time. That's not a high enough win ration to make it doable as an expansion strategy. The Skull Talisman really makes a noticeable difference, and I think part of it might be the free skeleton at the beginning, so that the assassination victim has more than one opponent at a time for most of the battle...

I admit that this is a highly questionable expansion strategy anyway. Even if your assassins win 100% of their battles, it still takes four or five Empoisoner-turns to take a province (3 or 4 to assassinate all leaders and one to attack). So at best, you can't gain more than one province per turn from turn 8 through 16 or so, and two provinces per turn after that, and so on.

I'm toying with the idea that one way to optimize this is to sneak right through the low-income provinces and head straight for the high income provinces first...