Something about FF Tactics’ battle system rubbed me the wrong way. It felt too artificial, a complaint I also have with the later FF RPGs.
On the other hand, FM 4 is awesome, partly because I found it for 10 bucks, but mostly because mecha combat is cool and this game is very well done. I might have to track down FM 3 if I ever finish this one.
There’s an odd game for PS1 called Vanguard Bandits that I liked. It’s also a mecha strategy game, but fantasy based - the mecha are powered by magic and can cast spells. I never finished it though, because the last few battles suddenly got insanely difficult. A friend of mine says he hates that game so much he took a belt sander to the disk, so it’s perhaps not for everyone. If you can find it for cheap it’s probably worth a look.