The number of stars in the Pleiades is a matter of subjective judgment, not a matter of objective observation. From the internet site irirangi.net I have copied this picture of Tauono, the six stars:

In my little astronomical hand book (Klepešta) a more detailed view will be found:

Counting the three to the right of the central four (Asterope, Taygeta, Celaeno) we will reach seven. If we disregard these and instead count the two to the left (Pleione, Atlas) we reach six. ('TAU' at bottom right means Taurus, not Tauono.)

If we should add both those to the right and those at left, we will reach nine. Did the Mangaians see yet another star as they had diamond-shaped kites with six feathers? No, I guess that only feathers should counted, six bunches for the Pleiades, three for the belt of Orion and four tufts in Pipiri (the twins and their parents). The corners of a diamond is another matter and should not be counted.