...Peranza is being very pliant here, and if Carissa can talk her into mutual Cooperation this way, she could probably also talk Peranza into Cooperating while Carissa Defected, which, as he understands it, Carissa should not really end up doing if she promises in the name of Law.

Well, everybody Cooperates the first time, and the older kids usually have to nag them for a while to get anyone to Defect for purposes of understanding the counterfactuals that real Civilization is meant to rule out.  Maybe Golarion isn't so different that way.

...Peranza is being very pliant here, and if Carissa can talk her into mutual Cooperation this way, she could probably also talk Peranza into Cooperating while Carissa Defected, which, as he understands it; Carissa should not really end up doing if she promises in the name of Law.

Well, everybody Cooperates the first time, and the older kids usually have to nag them for a while to get anyone to Defect ever, even for purposes of understanding the counterfactuals that real Civilization is meant to rule out.  Maybe Golarion isn't so different that way?  Still, Keltham would've thought the instruction to 'earn as much copper as possible' to maybe be a bit more effectively understood, here.

...Peranza is being very pliant here, and if Carissa can talk her into mutual Cooperation this way, she could probably also talk Peranza into Cooperating while Carissa Defected; which, as he understands it, Carissa should not really end up doing if she promises in the name of Law.

Well, everybody Cooperates the first time, and the older kids usually have to nag them for a while to get anyone to Defect ever, even for purposes of understanding the counterfactuals that real Civilization is meant to rule out.  Maybe Golarion isn't so different that way?  Still, Keltham would've thought the instruction to 'earn as much copper as possible' to maybe be a bit more effectively understood, here.