OK, about later SE's. They were moved down to take the GL and LX spot. Ford dumped the 'GL' trim name from all their cars in '98. So, the SVT took the top spot from the "real SE's".
One could get the Duratec V6 in any Contour trim, not just the Sport models. The same with Alloys, many Zetec cars have them. GL and LX Sports, with either 4 or a V6, were made from '96 to early 98. 1998.5-2000 SE Sports are V6 only cars.
I have a 2000 SE, no Sport trim, with a 6. I have seen LX and GL sixes.