If I recall, Transformers DS did have 3rd person shooting. But I also think it had hand-to-hand combat as well. Kind of GTA-ish I suppose.
If you're going to include Transformers, might as well include Gundam 00 as well. It's a beautiful looking DS game with robots that fly around shooting each other. Obviously I've never watched the anime so my knowledge is spotty on the details. And I've never personally played the game, though fans seem to like it a lot. Here's a trailer with gameplay-
As you can see, this boasts some of the best 3D on the system. It's smooth and impressive. There is some sword combat as well, but I think it counts as a shooter. Can't get over how impressive the game is! I'll have to try it soon. Sadly, it remains Japan-only and to my knowledge no patch is available.