I didn’t play the original Tactics Ogre, but I played a bit of the recent remake. It’s very much like FF Tactics, where you move individual units around on a grid, take turns, and adjust the direction they’re facing, etc.
Ogre Battle 64 is more like a full battle map with free, simultaneous movement. You traverse the battle map as sort of an overworld (?), then it switches to the autobattle combat interface when units run into each other.
They have some similarities, but I personally enjoy the Ogre Battle 64 approach more.
I had no idea what I was doing as a kid, and figuring out through trial and error which combinations and placements of units would cause them to do cool combo attacks was maddening.