Well, they've got spectral infantry. It's just that they don't have the paths!
You can get lucky with the F/D hero though ... but that only seems to happen to me in SP.
With CB1.3 you can try expanding without units. A Warlock Apprentice can take a province every turn it is supplied with blood slaves. Research Blood1 immediately (a great sage helps) and just use a couple calls of Call Lesser Horror (3 slaves). Together with your starting army you'll expand quite nicely. Barbarians and Elephants are tough to scare off because they kill your horrors too fast. Shoot the barbarians with indy archers and hire Beast trainers for any elephants.
You can do this with the following scales:
Order 3 Sloth 3 Heat 3 Death 3 Fortune 3 Drain 2
You won't be hiring much in the way of sacreds! But Warlock Apprentices can also cast Body Ethereal on Salamanders, and Demonbreds can support with Fire Blast.
So, CBM only: Blood-1, Evo-2, Alt-3, Const-6. Const-6 is for the lanterns mainly, but boots of youth don't hurt. A great sage can give you great diversity like:
Fire 3 Air 3 Water 3 Earth 4 Astral 4 Death 4 Nature 4 Blood 3
That's 44RP in drain 2. Shrouds at Const-4 give you regen for diseased Warlocks, and even at Const-2 you can make nice fiery toys for your indy commanders to blast away with.
Sacrifice with cheaper H2s to spread your dominion.
Without Lesser Horrors at Blood-1, I guess you could try Evo-2, Alt-3, Const-6. Use salamanders behind a few shields with supporting Star Fires and Fire Blasts. But you'll lose quite a few lizards without Body Eth, and you need a critical mass to defeat the enemy before you run out of gas.