those probably aren't referencing the exact same URL
for instance, in my history, i have one entry for 'forum.blockland.us' (bookmark) and then another for 'forum.blockland.us/index.php' (same page, different URL)
if you visit the exact same URL on the same day, google chrome will move that history entry to the top instead of making a new one
it doesn't make sense to implement such a thing here, and if you visit a server often, your list will be spammed with it and it'll make it very hard to find another server you went to in the past