Outside of the Big FiveGimmick titles - Every guild has some kind of gimmick title (or just gimmick) that makes it famous (or bomb)
It can be anything from inter gender title, name your own concept (famous in BCM,EEW and WWE:E)
Example
EEW has 10 titles over 3 brands, but this is because of the diversity of its members, but also member count.
they have 1 world title, 3 mid card titles (on each show), a hardcore, a cruiser type title, 2 tag titles, a womens, a developmental world title
Which was questioned to be too many titles, but there are plenty of people deserving a push that couldn't get one otherwise due to "politics"
So I say having the big 5 title wise is a good format to use and only expand if needed. If anything you can push to 3 or 4 if you deem the need
Lower Roster Count Format For Lower roster count (5-10) - World, Mid Card, Tag
This isn't counting women's but generally having a women's title division would involve at least 2 or more women.
Schevia
Here's a format for you that is completely incomplete and I have no idea where I'm going with this, but if you make sense of it, cool.
Let x = Number of members in each guild
Let y = Number of starting titles
Let b = Number of inactive people (completed and ongoing)
Let t = Number of titles you should have
As a rule, you have a default of 3. So that y ≥ 3
As a rule, you also have a default of 20 members to start. So that x ≥ 20.
In that way you'll have this: 20/3 ≈ 6 or 7 people/title.
So then the resulting formula is:
t ≈(x/y)-b
For example:
1 ≈ (20/3)-4
1 ≈ 6.67 - 4
1 ≠ 2.67
Therefore: No new title should be added. However, if for example you experience a growth by 10 members:
1 ≈ (30/3)-4
1 ≈ 10 - 4
1 ≠ 6
So with 6 new members that are active, it's plausible to add a new title.
And you can see why I'm not a math major.