For one thing, Tactics is set i the same Ivalice that XII is...yet XIV takes great liberties. Timeline wise FF XII took place long before Tactics, but in FF XIV it's reversed where the XII inspired stuff is happening recently and the Tactics stuff is ancient history. Details are also off. Like Fran being a general.
Things don't really line up with old games, and that's because FF XIV is simply adapting thigns into its own world without BEING those old worlds. Just like the gold saucer in FFXIV is not the FF VII Gold Saucer. Doma in FF XIV is not the FF VI Doma. Ivalice in FFXIV references XII and Tactics but it isn't the same version. For one thing, Ramza dies in the FFXIV version where as he leaves Ivalice in the Tactics version.