Gunbreaker unfortunately has a lot of shared models aka reskins already.

The Lakeland Manatrigger is a reskin of the Doman Iron Gunblade and the Coven Gunblade
Nabaath Manatrigger is a reskin of Molybdenum Gunblade
Gunblade of the Crimson Lotus is a reskin of the Ruby Tide Gunblade
The Deepgold Gunblade is a reskin of the Ghost Barque Gunblade
The Highsteel Gunblade is a reskin with the Padjali Gunblade

There are a lot of unique weapons, to be fair, and I think all of the Lakeland and Nabaath weapons were reskins, not just for gunbreaker. I think it's just more noticeable for gunbreaker because there are so few weapons for them in general.