Freelancer ID can engage other Freelancer ID when one of them is being paid for the work.
There's no team-killing in Discovery. The essence of "role play" here is that you play the role defined by the ID, so if the ID says you are police, then you role-play as a normal policeman would live his life, and not as "police gone bad killing all his co-workers"
Freelancer ID is one of the exceptions to this, but that is because Freelancer is not a "faction" so much as it is a non-aligned ship. However, Freelancers can only engage a target when they are being paid to do it, as per the rules in the bounty board. So ... Freelancer merc can hunt down other Freelancer merc, but cant just fly around shooting other Freelancers for entertainment. [Another exception is the Indy Pirate, which is allowed to pirate other pirates, and therefore requires the ability to engage them in combat, but only during the course of piracy.]
But if there was role-play behind it and the admins lik you then they will let the matter slide as good rp.
Basically that's my rule, good roleplay is whatever doesnt get you sanctioned