In this case it is kinda important. FF8 and FF9 were the most closely released FFs in the series. So much so that I suspect they came up with the concepts around the same time and decided to go at each project as differently as they could, on purpose. There were probably some minor graphical things they learned during FF8 that they could streamline for 9. 9 had more polys on screen, for instance. But it's fairly obvious that they were build on the same basic engine. FF8 team went on to develop FFX, while the FF9 team was largely made up of the folks who had done FF6, and later went on to do FFXII. FF7 was an amalgomation of the two which then split and regrouped. I'm not sure all my faces are straight about 6 and 7 though.