This is the actual answer to the question.
https://i.imgur.com/MDPpeDE.gif

Magelo shows each of the pieces as being less than a 1% drop rate. Each between 3 and 7 drops out of 829 recorded. Something with that low of a drop rate can have huge skews in either direction (getting 2 in a row or not getting one all night).

Also remember that Magelo is based on current EQ and most of the drops don't even exist in our timeline.

It is less than 1% if you are chasing after a specific piece, but if you want 'any Sentient piece' then you need to add them up together, including the axe, which adds up to about 5%, or 1 in every 20 kills

If you remove all the items that never dropped pre-Luclin, such as Defiant armor and some new trade skill components, Magelo is still quite accurate

What you also need to consider is the sample size, some mobs have few thousand kill sample in the database, but some only have 20 kills or less, which would produce not so optimal accuracy, also some mobs like named sirens in Sirens Grotto doesn't even exist in the database

Thank you!