I'm sure you can still see the similarities, though. I imagine any future SRPG would have AOE attacks involved. Just because they were not involved in FFTA doesn't mean that the next FFT game won't have them. I imagine the next SRPG will certainly take a long hard look at X-Com before they push it through and with good reason.

While FFT was all about classes, X-Com still had classes.
While X-Com was all about placement, placement/movement still came into play in FFT.