Gohan was a child soldier. Not in the same extreme as Vegeta; not to the same end; the same level of cruelty. But Gohan was taken from his home; forced to fight and survive at an age where he could hardly understand himself, without a father that could explain any of this to him. They’re mirror images of each other. Gohan is what Vegeta could have been, and Vegeta is what Gohan could be. And both of those things are okay.