So...why do regular civilliand even have a max level of 100?

[wattbatt]

I was upping max levels of some followers in the .esp, and i noticed that...many followers, that need to fight with you, have a max level of 30 or 50.

Regular girls like Ysolda instead have a max level of 100.

 

Just...why, lol? I can't make sense of this decision by the devs. What do you think?

[Dorabella]

24 minutes ago, wattbatt said:

I can't make sense of this decision by the devs.

There is more to it than meets the eye: the IA employed is practically absent. As I said somewhere else , put a mod with whores using a collar and , everyone will have that collar .

 

26 minutes ago, wattbatt said:

I was upping max levels of some followers in the .esp, and i noticed that...many followers, that need to fight with you, have a max level of 30 or 50.

Regular girls like Ysolda instead have a max level of 100.

It is possible for followers to be tagged as immortals (the Essential tag is enough to do this), while civilians such as Ysolda can easily be killed regardless of their level.
Since they are not equipped for battle anyway (they are still civilians), it is likely that they wanted to make up for this . 

[DocClox]

Izzy is a potential spouse. Maybe they wanted her to be able to handle herself the next time a giant decides to camp out in Lakeview Manor Gardens.

[Darkpig]

Bugthesda. No explanation needed.

[Fakenet]

Design decision.

That stat is unimportant for that particular character so you can set their skill level to anything between 1 and 100. Bethesda decided 100.