[Vocabulary] Two soldiers are standing guard on the top of the watch tower

[Marina Gaidar]

Is it correct to say "Two soldiers are standing guard on the top of the watch tower". I saw this word combination "stand guard" in the dictionary, but it somehow sounds strange to me. Is it ok?

 

[emsr2d2]

Why does it sound strange? It's a standard phrase. "To stand guard" means to be on duty, guarding something, normally standing up.