Interesting connections. Here is how my line breaks down.
My maternal grandmother was Julia Marija Kovac, here parents were Stanko Kovac and Gera Stimac, Stanko's parents were George Kovac and Marija Stimach. Gera Stimac's parents were Valentin Stimac and Marija (last name unknown).
My maternal grandfather was Ivan Anton Turk. His parents were Blaz Turk and Ana Pajnic, Ana's parents were Matija Pajnic and his wife was Marija (last name unknown.) Blaz's parents Juraj Turk and Jelena (last name unknown).
They were all from the Gorski Kotar region, and most from a village called Plesce' Croatia. Let me know if any of this makes a connection with your line.