If you swap the two characters in a compound word, and the meaning changes, then it is just a different word that happens to use the same two characters, e.g. 中心 (center) and 心中 (in the heart) are two different words;
If you can swap the two characters in a compound word and the meaning remain the same, it indicates the compound word itself is made up of two characters that have the same or extremely similar meaning, e.g. 打擊 --> 擊打 (both 打 and 擊 contain the meaning of 'hit'); 拯救 -->救拯 (both 拯 and 救 contain the meaning of 'rescue'
擊打(v) is a (not commonly used) variant of 打擊(v)
救拯(v) is a (not commonly used) variant of 拯救(v)
識見(n) is a (not commonly used) variant of 見識(n)
見識(v) and 識見 (n) are two different words
澄清(v) and 清澄 (adj) are two different words
In olden time, people often use this kind of variant to showcase their literary knowledge and sound more classical. You have to know what compound words are made up of two characters that contain the same meaning to be able to do so. In modern time, you can often find them in song lyrics when the writer needs to make it rhythm