I don't believe the family has 8 captains. The last time they had that many was 1982 and at that point they had as many active members on the street as there are total members now. 4 or 5 captains (including Licata, still in charge of the Newark crew as per the last reliable info we have) is much more likely and is consistent with what we've seen for the past 35 odd years.
Approximately 12 active soldiers, 4 or 5 captains and then the administration would put active membership at around 20-25. That's consistent with the estimates we've had over the past five years or so, and it's consistent with the growth in active members due to inductions and guys being released from prison.
Membership estimates we know of since 1994:
Following the Stanfa indictments, the New York Times estimated that there were 5-8 active Philly family members remaining on the street (including North Jersey)
After Ralph Natale flipped, the Philadelphia Daily News quoted a law enforcement source estimating there were 12-20 active members on the street (most likely including North Jersey and Boston)
In their 2004 report, the NJ State Commission of Investigation estimated that there were approximately 10 active members left on the street in the early-2000s
In 2009, Philly PD releases a chart of the organisation listing 13 active members on the street (though this chart was missing some known members at the time - including those guys the number of active members for 2009 can be estimated at about 15-18
Post-2011 indictments, DS and GA have consistently estimated active membership to be around 20-25, or 30 at the max (and I'd be more inclined to believe the lower end of that spectrum)