Added a visual of the refined layout after consulting a kitchen designer

Don't go with a grouping of square pendants ... unless you are ok with the pendants not always hanging perfectly square/aligned with each other.

I have 5 pendants hanging in a long hallway, more of an "octagonal" shape and sometimes wish I had gone with a round shape. My cleaning lady dusts them, which moves them and eventually one will no longer line up. I then have to get my tall stepladder to adjust from the top and get it lined up again.

As far as size, get some cardboard, cut it to size and mock up the different options. Hang it up with some string and blue tape. You won't regret doing this bit of extra work.

I would not do THREE pendants, I would do two larger or a linear light - and you might tell us the dimensions of the island ? Please? 12 feet ? I don't understand the glam shine in your light selection - based on the rendering : )

More width. You don't need to fill air above the island. Make certain specs and enough wire, to allow the light 72 - 74 inches bottom of fixture to floor, or 36 to 38 " bottom of fixture to counter top

A linear fixture is the easiest to place. No worries about lining up several fixtures. One box and you're done!