>>2764521Ogre Battle just talks about Zenobia's war and there are some characters that appear in Tactics Ogre like Canopus, the PSP remake actually has more references than the SNES/PSX versions, so yeah, if you care about the lore you should play it, so at least you get an idea of what happened to some characters who appear in TO, like Canopus or Lans.
There's also other subtle references with characters like Radlum but they're very minor and only serve as lore cohesion characters or cameos.
Basically, by playing OB you'll get a bigger picture of what happens in the Ogre saga, especially regarding Lodis, but TO is really self contained for most things.
The GBA game is the one that needs knowledge of the other ones to be enjoyed fully, but it's not really that good of a game outside of the lore and plot points and it's not even retro, but if you're interested in the series you might want to give it a try.