They're 3 letters different, with only the J trait in common xD
In a nutshell: Crow is charismatic/social, a bit of a visionary, and not very in tune with his emotions; while Penelope is reserved, down to earth, and empathetic
They both feel most comfortable when they have a plan though, so there's that lol
Also the ENTJ and ISFJ approaches to relationships are both really interesting, since they both seek long term commitment, but go about it in very different ways

Do you know what Gavin's personality type is yet? I'm curious now x3