It's all up to you, everything that is sacrosankt are solid choices, from blightwar there is not very much you can grab (longstrike raptors) and everything else is just weaker then new chamber, but can perform decent.
Three of SCE main weaknesses are Bravery, Speed and Damage so you will need to focus on those, as well as having enough chaff and roadblocks to protect your heavy hitters (since you don't have a luxury of heavy-hitting roadblock that is 20 sequitors) and score objectives
As for heroes Incantor and Castellant should probably be your go-to choices, Azyros now can buff melee, while Heraldor's buff is really good if opponent is trying to tie you down
Maybe it's just my bad rolls, but I see a tendency to get heavy losses from battleshock. That is something to remeber about.