Worstgen
Garp the Fist
I don't know, tbh, can't remember it ever been mentioned in manga or an SBS. Logistical stuff like that doesn't really grab my interest in OP, so it could have been brought up at some time in the last and I just haven't remembered- I didn't even know G5 had at least 55
Monkey D. Luffy
That's G-8, the filler base.
Garp the Fist
Ah, didn't read that right, sorry. In that case, I wouldn't even know how canon that is- my knowledge of the G-8 is slim to none, but I do know that they made the good guy Marine leader a disciple of Sakazuki, suggesting they may not have been working all that closely with Oda for the arc
Monkey D. Luffy
Would 55 units be too much?
Garp the Fist
Depends- how many men are in a unit? As far as I've been able to find out, here's the Marine numbers we know for canon. A Buster Call battleship has 1000 men on it. At Marineford the Marines had 50 battleships and 100,000 troops in it, so that's 150,000 men, presumably a fair chunk of their Paradise manpower, with some New World as well. G-5 has 300 men in six divisions, so presumably 50 men a division.