no, it seems you're still mistaken.)

the difference is more than 10%. you don't seem to be taking specialization into account, and that's what the whole discussion is about.

It receives an additional 5% per level to the percentage skill of Spellcasting. The number of summoned units (%) is calculated using the formula:

k*(1+0.05*Level),
where k = 10 for the basic level of the Spellcasting secondary skill
k = 20 for the advanced level
k = 30 for the expert level
The maximum significant level of this skill is 100%