Tactics win battles, strategy wins wars.
As an example of the difference, even though they are both grid based games, there is a significant difference in overall movement and playstyle(in certain ways);
Movement in Final Fantasy Tactics is more limited in some ways than Fire Emblem; Typical movement ratings for characters range from 3-4, in some situations able to be boosted to 5-6, and in even rarer situations, getting up to 7-8(as in, a Chocobo Knight on a White Chocobo with Ninja Tabi is the only way to get 8 movement, and I don't even know if that would work). Enemies are typically the same move speed or slower. Characters can jump up elevation up to their Jump rating with no penalty, and can some times jump over gaps or obstacles(presumably, as far as I can tell, this adds 2 to the effective elevation), also without move penalty(though the panel jumped does count towards movement for the round). This elevation is what typically presents movement challenges(besides impassable terrain), and other than water(which certain races can't enter, but works normally for all others), all terrain is effectively the same; nothing costs additional movement.
Movement in Fire Emblem is typically in the range of anywhere from 4-6 for typical characters, reaching 10 for things like Nomad Rangers on plains. Some terrain blocks movement, some costs additional movement, especially if you're of one movement type or another.
However, the balance to this is how ranged attacks work; in Fire Emblem, ranged weapons and magic vary from 1-3 range, depending on the exact things involved. In Final Fantasy Tactics, they have a max range between 4 and 8, typically, and just because someone is adjacent to you doesn't mean you can't shoot them in the face.
Also, it's a matter of whether you choose your stat growths, are stuck with them, and just get a set of stats,(Fire Emblem), or whether your stat growths depend on your job when you level up/the main one you'd been for that level, can affect your stat growths overall only slightly, and can choose your own stats(plus being able to switch jobs).