It's not a coincidence at all, but not for the reason that you think. The traditional date if the expulsion of the Tarquins must be a later tradition attempting to imitate the Athenian one. That Rome had kings and that some of these kings were probably Etruscan is pretty certain, but the precise dating of the expulsion of the kings and the exact events as described by later sources like Dionysius of Halicarnassus and of course Livy are certainly an invention. The expulsion of the kings by two leaders, one of whom is incited by sexual assault (Collatinus for the Tarquins and Harmodius for the Pisistratids) against a female relative by a younger relative of the tyrant (Lucretia by Sextus Tarquin or Harmodius' sister by Hipparchus) is simply too obviously an imitation of the Athenian story to be accurate, and generally scholars dismiss the story as it is presented. I mean, for Christ's sake the Tarquins were expelled in exactly the same year as the Pisistratids, 510. This isn't the only time when we see obvious attempts to link the pre-Republican or earliest Republican traditions with Greek traditions of about the same period. Stories like Horatius Cocles and the sacrifice of the 300 Fabii are both quite obviously influenced by the defense of Thermopylae. These stories probably are based on something real (obviously the expulsion of the Tarquins is based on something that actually happened, as the kingship at Rome ended after all) or at least are based on older native traditions, but the Greek influence of obvious and very much there