Quote from BlazingRagnarok »I really liked what I was reading until I got to the point where you decided to tack the artifact thing onto Duplicate, at which point I went "wut." You're repeating the exact same mistake you made when you tried to drag artifacts into your RW color pair.
Unless the whole set has an artifact theme, like with Kaladesh and Aether Revolt, mono-green cards have no business with artifact synergy because artifact mechanics are so low of a priority in green's color pie that they require a high level of set-wide saturation to be justified. Unless you want your GU color pair, particularly mono-green cards, to have artifact synergy of its own completely independent from other color pairs, I would not recommend having Duplicate make artifact copies.
Inter-pair wedge synergy is great, but you want to achieve it via organic means, not by having one color pair take over its neighbors. Artifact creatures with duplicate are a good solution, but green creatures that spit out artifacts for the sake of red cards are not.