When you have the familar set to follow a sequence, that sequence advances whenever you cast a skill
From the description, my thought was that this sequence would advance whenever you summoned the familiar, so that it would be possible to have all three types available.
Is this a bug or intentional?
with the unique glove you get all three types on 1 cast.
also if your laying your spells like casting firebolt, then familar, then frozen orb, then familar, then lightning spear, then familar you get all 3 types without the sequence thing
That should be a bug. The description lists the order it goes in and removes the need to cast a skill.