Yeah that was there in the Vinella versions of KH1.
You're meant to attack them without them seeing you. They see you, they respawn quickly and attack ruthlessly.
And the new heartless beat my ass last time! ( haven't died on bosses, but normal heartless? that's a new one.) I was in Traverse Town and I saw this like dark purple girl monkey (y'know the girl ones that throw bananas in Deep Jungle?) And I went to fight it because I'm like, "Pssh, it's the girl monkey, I can take it." Ha, diddly that! I go near it and I see this like crosshairs on me and I keep getting shot at and I'm like WTF is that!? And there's a mob of these... and in like a minute I got killed... and it's like WTF was that?!
You're meant to attack them without them seeing you. They see you, they respawn quickly and attack ruthlessly.