Ok, so at the moment, Togepi is way, way too low.
The amount of training he needs to be good is almost non existant. As a matter of fact, I recorded rough records of his battles during Route 32, and he didn't even participate in all of them.
Battle 1: Lvl 6 Wooper. Switched out first turn. Lvl 3
Battle 2: Lvl 4 Ekans. 2RKO, Lvl 4
Battle 3: See battle 1, Lvl 4
Battle 4: Trainer, Lvl 8 Nidoran. 4RKO, Lvl 6
Battle 5: Lvl 6 Wooper. 3RKO, Lvl 6
Battle 6: Trainer, Lvl 9 Nidoran. Switched out first turn (although he probably could have handled it), Lvl 7
Battle 7: Lvl 4 Ekans. ORKO, Lvl 7
Battle 8: Lvl 6 Bellsprout. 2RKO, Lvl 7
Battle 9: Trainer, Lvl 10 Wooper. Switched out first turn, Lvl 8
Battle 10: Lvl 4 Zubat. ORKO, Lvl 8
Battle 11: Lvl 6 Wooper. 2RKO, Lvl 8
Battle 12: Ekans. ORKO, Lvl 9
Battle 13: Wooper. 2RKO, Lvl 9
Battle 14: Trainer: Lvl 10 Goldeen. 4RKO, Lvl 10
Battle 15: Poliwagx2, 2RKO, Lvl 11
15 battles later that didn't involve me going out of my way, and he's already Level 11. Then I get to the Dark Cave where he initially 2RKOs everything (only 3RKOing a trainer's Onix I believe), and takes miniscule damage from everything. By the end of the cave, he was ORKOing most wild Pokemon. Extrasensory kicks enough ass to make training Togepi a breeze. Certainly more then any Pokemon coming later in the game (I'd actually say any Pokemon after around the fourth gym that doesn't come at a reasonable level is a liability).
I think he belongs in around Upper Upper Mid. I'm willing to bet he's MUCH easier to train then somebody like Gastly, Zubat, or Abra who don't get a decent attacking move for ages. I think I'll catch one of the above Pokemon, and compare their training experiences.
EDIT: Zubat caught at Level 5 in Union Cave. Battles will be done on Route 33.
Battle 1: Lvl 7 Ekans. Its skill prevented Zubat from switching out, so it died. Judging by the amount of damage Leech Life was doing though, it was probably going to run out of PP before Ekans died. Lvl 5
Battle 2: Lvl 6 Ratatta. Switched out first turn. Lvl 5
Battle 3: Lvl 6 Ratatta. Switched out first turn. Lvl 5
Went to Union Cave for a bit
Battle 4: Lvl 6 Geodude. Played through the battle just for kicks. Ran out of PP for Leech Life before Geodude died. Switched out.
Battle 5: Lvl 6 Ratatta. Switched out after almost dying. Lvl 6
Battle 6: Lvl 7 Zubat (lol). Switched out first turn. Lvl 6
Around this time I looked up when Zubat learns a new move. That would be Lvl 9, Astonish.
At this point I stopped training Zubat.
tldr: Togepi gains exp like a madman, has a kickass move right off the bat, and requires one route of normal play to be on par with the rest of the team.
Upper Upper Mid this guy.
Note: Togepi hatched before Route 32 due to visiting the Ruins of Alph beforehand.