The buff Orpington is still young and he might not know how to properly mate with the hens yet. The hens don't want him becouse like @bobbi-j said, he's still immature. I also have a 5 month old cockerel right now. He's trying, but he just can't get the hang of breeding yet. For that reason, my hens aren't too interested in him. The only difference is that my boy is the only rooster in the flock.
Don't keep the Maran. I don't think it's worth risking it. As the buff Orpington matures, he'll be better to the hens and I think he'll turn out to be a way nicer rooster.
Don't keep the Maran. I don't think it's worth risking it. As the buff Orpington matures, he'll be better to the hens and I think he'll turn out to be a way nicer rooster.