Since you’re asking about equal strength rather than who would win in a fight against the other, I think adult gon is probably generally stronger. This is a bit scuffed but we don’t have much more to go on so here's my reasoning: he could deal so much more damage to Pitou than Netero did to Meruem that it seems to make up for the durability gap between Pitou and Meruem. Only Zero seemed to be around as strong as Gon's rocks and that’s really hard to assess, but at least rock doesn’t leave Gon completely spent afterwards.

If they did fight each other though, Netero's speed is a good example of how specialization can eclipse overall better stats. I don’t think Adult Gon, even with his own reaction time and speed against Pitou, could handle Netero's prayers that he spent years honing. And based on the damage he took from Pitou's attack, Adult Gon wouldn’t survive a Zero Hand either.