...some thoughts from my side...
you have to pay the roaming penalty all the time... so you may reduce the site number or cut the roaming penalty... you make your minions already roaming by the way...
or use a gollum "engine":
it draws him,
led astray...
sweeter meats! -->
gollum skulker with
incited?
Gollum makes pool and makes your minions cheap - you profit in two ways
Gollum prevents direct damage
Gollum push your minions (lurker!)
...then you could cut
flames within and a few other orcs perhaps... and you can also exert Gollum for making Sauron cheap!
...but I guess, this is not that what you expected to hear... I will keep thinking about it...