Ignore it.
In fact, the level-scaling is the only frustrating thing about the PSP remake of Tactics Ogre. Newly recruited classes start at level 1, which means you'll have to drag them into battle and stick them at the back so they can gain levels from the shared experience. This is irksome, but it does not break the game by any measure.
Everything about the PSP version of Tactics Ogre improves on the original, which is an annoying mess by comparison. The PSX, Saturn, and Super Famicom versions of Tactics Ogre all date back to 1995, and they're full of archaic and tedious concepts. You're forced to fight boring mock battles to bring lower-level characters up to speed, characters do little to no damage against enemies unless they're at the same level or higher, experience is awarded largely to characters who land killing blows, and area-effect spell animations play EVEN WHEN THERE'S NO ENEMY THERE. Also, you can't resurrect fallen allies, you can't backtrack in movement, and you can't do a lot of other helpful things that you can do in more recent RPGs. Oh, and the PSX version has terrible loading times and a mediocre translation. It has some great moments, but so much of the game is a chore.
The PSP version fixes all of this. The battles flow much better, you can build up your levels without grinding, the skill system (similar to Final Fantasy Tactics) is excellent, and the dialogue actually makes sense.
Also:
-Archers aren't overpowered
-Magic users are rather useful, as they have numerous effect spells that warrior classes never get.
-Kupomogli is known for complaining about "flaws" that are either irrelevant or entirely made-up
I normally don't make serious posts here because these forums just aren't worth it anymore, but I hate to think that someone would play the sluggish, outdated original Tactics Ogre over the massively improved PSP version.