As I was doing yet another read through of 3f, I noticed a concept I could borrow from Torchbearer for Engagement rolls:
Before the players decide which of the 6 plans they are using, assign a base vulnerability to each plan. Torchbearer does something similar with monster design with regard to conflicts. The “hit points” of the monster are dependent on which conflict you enter, but the GM has pre-determined the distribution to keep it fair with regards to player autonomy.
So you might set Assault at 4d for a market vendor’s stall, whereas the armory might have a vulnerability of 0d for Assault. Approach the armory with an Occult plan and you might have 3d for Engagement.
Go one further: each possible job you lay out gets this treatment. As the crew does other jobs around town, the vulnerabilities get adjusted due to reputation/heat. The armory used to be ill-prepared against an Occult assault until the last couple of jobs where the Whisper was less than subtle… Now the armory has asked the Dimmer Sisters for help. Occult is now 1d. Oh you’ve worked with the Dimmer Sisters before? Now it’s 0d because they know how you work.