I'd be surprised if they start yet another show unless they cancel another. If they spread themselves too thin they could suffer diminishing returns both in terms of talent and in audience retention.
Depending on how things shake out, I suppose it's possible that they could free up a spot by merging 'Luke Cage' & 'Iron Fist into' a 'Heroes for Hire' show in lieu of a second season for each.
Depending on how things shake out, I suppose it's possible that they could free up a spot by merging 'Luke Cage' & 'Iron Fist into' a 'Heroes for Hire' show in lieu of a second season for each.

I still am looking forward to see where they take the show and am curious how much they will go with the character and backstory given that he's trained to defeat The Hand (i expect many hallway fight scenes even more spectacular than the already awesome fights of Daredevil).