Those NT5s may end up sounding too bright given what the source material is. I'd advise looking for some darker mics if you can find them.
Also, I'd experiment with many different mic positions on the anvil. What you're looking for is going to be incredibly difficult to capture well with just one setup. Give 5 good whacks (allowing time for ringout between each hit), then move the mics, rinse repeat.
Don't be afraid to aim the mics away from the anvil on some takes, and also to move them at least 10 feet away on some takes Put them under the table the anvil is on as well.
then, in post you can combine the different persepectives into a single hit captured from multiple angles.
I once did some bat hits at a major league batting practice that way. I only had one mic on me (416) and didn't expect them to start BP with no music on. When it started happening I aimed at the batter for a few hits, then started aiming at various reverb points in the stadium. Combined them all up and got the most realistic bat hit sound in my library.