How does the engagement roll work if the PCs want to split up? For example the spider wants to talk their way in while the lurk wants to sneak in a back way? Maybe because they have 2 objectives for the job.
There is guidance in the rules for multi tiered plans (you just do multiple engagement rolls, resolving one after the other).
But splitting up isn’t really an issue in blades if they are going after the same thing. Likely the main task of the score can be worked on by players who might be miles apart (you distract the bluecoats in the docks district while we raid their headquarters).
Players can always meetup later or in flashbacks.
If your concern is how do you allocate dice based on multiple approaches, I’d say find one that fits both methods. But remember that the main hurdle to starting a job can be glossed over. Maybe that was just getting in the gate?