[Shooter 2.5]

The statute of defence of property is not under self defense. Texas law allows the defense of property even when the suspect is running away.

Read the statute.

[WL-law]

I did read the statute -- and I read your inserted comments. Here they are.

(1) if he would be justified in using force against the other under Section 9.41; and [See the other section]
(2) when and to the degree he reasonably believes the deadly force is immediately necessary:
[The guy was approaching with a hammer] (bold added)

In your facts you are emphasizing the guy with the hammer. That sounds like the 'actor' is physically in fear of harm, i.e., a self-defense situation. And then the inquiry is, is the fear reasonable and the response necessary? And that is at the heart of traditional self-defense formulations -- hence my point.