Lovely piece - very interesting for Aurliano Toso.
Not all the Marten's pieces are catalogued, so it is possible that he designed it. However, it is not what he is know for doing. As you point out, he did a wide range of styles. In Heiremann's book on Martens, there are pieces in the back cataloge pages that one would never guess were by Martens, especially the human figurals.
I think you're safe thinking that Martens probably designed your decanter.