Neat dioramas ! Great work on them both.
The first 2 shots are of a Sd Kfz 164 Hornisse (early Nashorn) armed with the 8.8cm Pak 43 anti-tank gun. The Sd Kfz 165 Hummel was a similar vehicle, but armed with the 15cm sFH18 Howitzer.
The Nashorn diorama looks really cool. In the pics, it gives the appearencce of a rainy/gloomy day. Vehicle, figures, and the groundwork are done very well. Your diorama "tells a story" for the viewer, which is good.
Brummbar diorama looks good too. You should post more pics of both of these if you can.
Cheers !!
Alpen