Goten and Gohan before the RoSaT training were comparable to each other, and Gohan had only grown out of the shape in between the Cell Games and the Majin Buu Conflict, with the Daizenshuu going so far as to state that his power simply stagnated rather than decreased, meaning that even SSJ Goten > SSJ Goku from the Cell Games, so that's not a very good one. It's also implied that base Gotenks did better against Innocent Buu than Majin Vegeta did, as Gotenks actually came back from the fight alive and conscious, with the Daizenshuu once again backing this up by stating that Gotenks surpassed Vegeta upon birth, the same Vegeta who surpassed SSJ2 Gohan from the Cell Games, meaning that base Gotenks > Super Perfect Cell. So, these matchups involving the Cell Games are not very fair.