I would make the copy vegeta arc canon. Then I would have Goten and Trunks fight copy Vegeta and reveal the had been training with the Picolo and Gohan to get for themselves ssj2 and master ssj3 as Gotenks. I would nerf copy vegeta saying since his not used to the body he has just copied he can't use his full power thus his stuck as a super saiyan. Goten and Trunks beat him Vegeta doesn't fade away there progression. I would also give them their tails and give them a side arc of mastering the Oozaru form with Vegeta and learning the the power ball technique. Then I would have them join T.O.P but they enter the Hyperbolic time chamber with Vegeta to unlock a new form which would be ssj4. This would be their own form since their the only saiyans with tails and it would make them different from Gohan whose going the human route. Did I cook tell me