The founder Mike Lee Kamerick/Kanmerk/something like that... states that he draws heavily from Krav Maga in the Haganah system. To it, he claims to add elements of kapop and lotar (of which I admitedly know nothing). I have reviewed the DVDs from the FIGHT series and studied Krav Maga for about a year. It appears that the differences are mainly in the focus. Haganah is technique intensive and, from my exposure to Krav maga, it seemed to be very movement oriented (read: footwork).
Not an expert at either form, but I greatly admire the nature of both...they have influenced how I teach self-defence and close quarters combat.
My two bits..