Gohan could gain better control over his emotions during training with Whis. This is important because in battle, a clear - headed fighter is more likely to succeed. Whis could teach Gohan how to stay calm under pressure, which would enhance his performance in fights. Also, Gohan may learn some unique moves that are exclusive to Whis' training regime.
Well, if they were brothers in a fanfic, it could change how they interact with the other characters. Maybe they'd have a deeper understanding and fewer power struggles between them. Also, their family background and upbringing could be explored in new and interesting ways.
It's a bit hard to say for sure. Both Vegeta and Goku have their moments of strength. Goku has some unique powers and techniques that give him an edge at times, but Vegeta is no slouch either and constantly works to catch up and surpass Goku.
Generally, Goku still holds the edge over Vegeta. Their power levels fluctuate, but Goku often achieves higher peaks of strength and unlocks more powerful forms first.
It often starts with a shock or surprise at the mpreg situation. Then, they gradually learn to rely on each other more. For example, Vegeta might start to show a more caring side that he usually hides, and Goku might become more responsible. They'll have to communicate more, sharing their fears and hopes about the future with the baby.
There might be some out there, but such a concept goes against the more common friendly - rival dynamic between them in the original series. It's not a very popular or positive take in the mainstream fan community. However, in the vast world of fanfiction, you might find some that explore this in a creative, non - malicious way, perhaps as a what - if scenario in an alternate universe where their relationship took a different turn.
One possible analysis could be that it often explores the dynamic between two powerful and complex characters. Goku Black, with his menacing and somewhat twisted nature, and Vegeta, the proud Saiyan prince. In fanfics, their interactions can range from intense battles to unexpected alliances. Maybe it delves into how Vegeta would react to Goku Black's presence, given their different ideologies and power levels.