The FF DS are... they're not just ports but remakes with things tacked on it all the time. FF4 is a lot harder and much different with the augment system than the original... and the normal monsters can be pretty troll-ish. FF3 I heard that because the DS couldn't handle the number of enemies on a screen at once, they kinda buffed up the numbers on the monsters so that maybe the cause of a lot of grind? Really in general, early FFs don't really age that well haha. It's only FF4 and on when there's more serious attempts at a sensible plot that FF made its name.