Cool idea, Mike. These kinds of games can be lots of fun.
Yes, the Pulp Alley rules and Fortune cards are already written to include this style of play. So when 2+ players form a team prior to the start of a scenario, then their characters become "friendly" but they are not colleagues.
Note, we are VERY specific in our use of the terms like opponent, friendly, enemy, character, colleague, and so.
Some examples....
You cannot normally play a Peril on a teammate's character because they are not an "opponent".
Not So Fast can be played on any character - so you could impair a teammate.
Give or Take can be played on any challenge - so you could make a teammate's challenge easier
or harder.
Hit or Miss can be played on any player - so you could make a teammate's Health check easier
or harder.
Ain't Over Yet can be played after any fight - so you can make two characters continue fighting even if neither is yours (a personal favorite).
More examples......
A character with the
Doc ability can treat a "colleague" - not a friendly (teammate).
Stunned can only be played on an enemy - not a teammate.
Misfortune can only be played on an opponent - not a teammate.
Bad Luck can only be played on an enemy/opponent - not a teammate.
Unseen Peril can only be played on an enemy - not a teammate.
You may transfer a Plot Point to a "colleague" - but you can not transfer to a teammate.
Although we see it fairly often, trying to form a team after the start of a scenario is simply a gentlemen's agreement. This sort of thing does not actually change any designations.
Of course you should always feel free to make adjustments that you think will add to the enjoyment. One thing I've done in the past, is to have players in teams for 3 turns and then end all the teams at the start of turn 4.
You've already run enough of these that you know what you're getting in to, but when I have 6 players around the table I always run everything by-the-book and avoid adding any special rules. When I have 2-3 players, that's when I add in crazy stuff. When I have 6 players, there's already enuff crazy.
HAVE FUN