We have over 40 moderators, managing around 40 public sections. Around 100k posts per month give or take..

1 admin, 10 mods. :)

It all depends on the size of the board.
I am the only admin, 2 super mods and 4 mods.

10 excluding myself

Moderators - 5
Super Moderators - 5
Administrators - 1 (Me)

Members: ~17,000

Not all the time.

6 including me with 13,000 members.

We don't even need that many, no one gets out of line or does anything inappropriate for some reason.

2 owners, 7 admins , 10 global admins , 60-70 forum moderators (52k+ members)
something like 70-80 forums..

Just a comment. IMO, since this is a big boards forum, I think is inappropriate to start with something less then 20, for the number of staff members in the poll.
I'm more interested to see the forum subject/no. of posts/staff ratio, then just the number of staff members. It does not help me with nothing to know that you have 120 members on your staff line.

Example:
Acura related > 10mil posts > 45 staff members
Graphics related > 20mil posts > 10 staff members

Now, I know that automotive requires more attention, then graphs. :)
Basically, the more staff members you have the better your forum is controlled.
However, it can also mean that you deal with a lot of troublemakers.

Let me know if my idea/logic is good.

Yes your logic is good :)

2 Owners
3 Admins
3 Super Mods
4 Moderators
12 in total
Threads: 6,062, Posts: 10,732, Members: 2,763
Total members that have visited the forum today: 110
New Registrations per day: 30-60

We have been around for about 3 months total.