Gohan during the 7 year timeskip...

[Future Warrior]

Probably wouldn't have gotten much stronger even if he did train intensely.

Think about it. Future Gohan had to train himself solo for longer than a decade, yet the power he reached is completely dwarfed by what his child version in another timeline had achieved in a year under the right circumstances. It seems like he isn't able to reach new heights on his own and requires someone to guide him. That's why I believe Gohan wouldn't be much stronger than he was during the Cell Games, and 100% would not reach SSJ3 or whatever.

 

[SSJ2]

He could’ve trained with Goten.

 

[Future Warrior]

Gohan didn't know he was that strong till he was 7 though.

 

[Papasmurf]

He could've trained with Piccolo though.

 

[Pocket-Gog~]

He could've trained with Beerus.

 

[SSJ2]

Or he could've killed himself so he could train with Galu.

 

[Papasmurf]

Or he could've killed himself so he could train with Galu.

I never understood why Galu didn't just teach him how to use IT so they can meet any time even if he died

 

[GreatSaiyaman123]

He already had the power within him, the issue was mastering it. I think he could’ve perfected SSJ2 on his own since this is the kind of training that should be done alone anyway.

He also had Goten to spar with. If he bothered to train he might have discovered Goten is into fighting too.

Or he could've killed himself so he could train with Galu.

I never understood why Galu didn't just teach him how to use IT so they can meet any time even if he died

Probably didn’t have the time. Even the guys who invented the technique took months to help Goku learn.

 

[Papasmurf]

He already had the power within him, the issue was mastering it. I think he could’ve perfected SSJ2 on his own since this is the kind of training that should be done alone anyway.

He also had Goten to spar with. If he bothered to train he might have discovered Goten is into fighting too.

Or he could've killed himself so he could train with Galu.

I never understood why Galu didn't just teach him how to use IT so they can meet any time even if he died

Probably didn’t have the time. Even the guys who invented the technique took months to help Goku learn.

He had 3 years to train with Gohan and Piccolo prior to the androids showing up lol...

 

[Captain Cadaver]

Future Gohan was also constantly trying to avoid being killed by #17 and #18 as well as living in a reality where good resources weren't really a common thing, so not the best comparison. He also lacked any significant training partners with Trunks only having grown his SSJ form to the level of rivalling Gohan's base self at the time of his death, so sparring wouldn't be as beneficial as Gohan paying a visit to Piccolo or Vegeta. Pretty sure there was also either a Toriyama interview or guidebook entry that made note of Saiyan hybrids developing their power better in peaceful environments as an explanation for how Present Trunks went SSJ so early and easily, which should apply to Gohan's power development as well.

He had 3 years to train with Gohan and Piccolo prior to the androids showing up lol...

Goku's main goal for Gohan was to make him stronger though, something that would be hindered by taking time out to teach him Shunkan Ido. On top of that, Gohan was far less experienced than him and it may take him far longer to learn the technique. There'd be more weight in criticising him for not teaching Piccolo instead, but what we see of Goku's tutoring also shows he isn't the best at explaining deeper concepts such as the Yardrattians' unique manipulation of energy, plus Piccolo would've likely placed priority purely in getting stronger too when considering he made it apparent he wanted to get as strong as possible in those 3 years and wouldn't want to hold Goku and Gohan's training back either.

 

[Papasmurf]

Given that they were dealing with SSJ tier enemies and Gohan really didn't do much of anything besides one sneak attack on Dr. Gero, I'd say teaching him Shunkan Idou would've been far more beneficial in the long run, especially since Gohan's most major gainz in the arc were through the RoSaT anyway.

 

[Future Warrior]

Gohan paying a visit to Piccolo or Vegeta.

I can't see Vegeta wanting to spar with Gohan. Maybe Piccolo but I'm questioning how much he's able to push him to new heights.

 

[Hector]

I think he would be as strong as his Post Z Sword self.

 

[Captain Cadaver]

I can't see Vegeta wanting to spar with Gohan.

Vegeta seemed pretty keen to see how Gohan fared against him at the start of the Boo Arc, so I doubt he'd pass up an opportunity to test his training gains.

Maybe Piccolo but I'm questioning how much he's able to push him to new heights.

More beneficial than his future self sparring against someone barely a match for his base form, at least.

 

[Symbiote]

Vegeta knew how strong Gohan was and knew he couldn’t match up. He only wanted to fight him because he knew he turned into a plug.

 

[Captain Cadaver]

Vegeta made it apparent Gohan had slacked off more than he thought by the time of the Budokai and his initial estimations were purely physical ones rather than anything in-depth, yet he still had confidence in being at the top of the pecking order.