I'm not necessarily trying to prove that it's the case. I'm just saying that, since the Buu Saga will always have contradictions no matter how you view the power scaling, it's better from a writing point of view to see it this way.
1. From Goku's statements about the fusion between Goten and Trunks, we can deduce he just expected that a warrior stronger than him would come out of it somehow. He didn't know exactly how that would happen, he just hoped it.
Who was that warrior? Base/SSJ Gotenks (both pre and post ROSAT) served just gag purposes. Obviously they were not intended by the story to be those who would fulfill Goku's hopes.
2. When Goku saw SSJ3 Gotenks, he was impressed at how the children reached a level of power it took him years to attain. Of course, one can argue that he was talking about the transformation, not the power level. But either way, it doesn't feel to me like there would be any point in that comment if SSJ3 Goku was a small fry compared to SSJ3 Gotenks.
3. In the cover of the 25th volume of the manga, SSJ3 Goku, SSJ3 Gotenks, and Ultimate Gohan are about to fire together. To me, that paints a picture of them not being leagues away from each other in power.
4. Fat Buu (pre split), Super Buu, and Kid Buu don't have to have different power levels.
Fat Buu's transformation could be bad news and serve a dramatic purpose in the story even without his power changing: his body becomes more athletic and his heart more evil. Furthermore, Goku made about the same statement for all three Buus: that he can't beat them.
-About Fat Buu: He's mighty strong. I don't think I could've beaten him.
-About Super Buu: He'll kill us if we go out like this.
-About Kid Buu: This isn't what I thought it to be. We should have fused.
All in all, from a writing point of view, it's best to view those three Buus as different manifestations of the same power. With any of them, Goku could put up a good fight, but he was doomed to lose due to the SSJ3 form draining his stamina.
In short, Goku is about at the same level as the three Buus, and SSJ3 Gotenks is a little stronger than that level.
1. From Goku's statements about the fusion between Goten and Trunks, we can deduce he just expected that a warrior stronger than him would come out of it somehow. He didn't know exactly how that would happen, he just hoped it.
Who was that warrior? Base/SSJ Gotenks (both pre and post ROSAT) served just gag purposes. Obviously they were not intended by the story to be those who would fulfill Goku's hopes.
2. When Goku saw SSJ3 Gotenks, he was impressed at how the children reached a level of power it took him years to attain. Of course, one can argue that he was talking about the transformation, not the power level. But either way, it doesn't feel to me like there would be any point in that comment if SSJ3 Goku was a small fry compared to SSJ3 Gotenks.
3. In the cover of the 25th volume of the manga, SSJ3 Goku, SSJ3 Gotenks, and Ultimate Gohan are about to fire together. To me, that paints a picture of them not being leagues away from each other in power.
4. Fat Buu (pre split), Super Buu, and Kid Buu don't have to have different power levels.
Fat Buu's transformation could be bad news and serve a dramatic purpose in the story even without his power changing: his body becomes more athletic and his heart more evil. Furthermore, Goku made about the same statement for all three Buus: that he can't beat them.
-About Fat Buu: He's mighty strong. I don't think I could've beaten him.
-About Super Buu: He'll kill us if we go out like this.
-About Kid Buu: This isn't what I thought it to be. We should have fused.
All in all, from a writing point of view, it's best to view those three Buus as different manifestations of the same power. With any of them, Goku could put up a good fight, but he was doomed to lose due to the SSJ3 form draining his stamina.
In short, Goku is about at the same level as the three Buus, and SSJ3 Gotenks is a little stronger than that level.
