drop back vs hang back

drop back and hang back both are verbs.

Word	Noun	Adjective	Verb	Adverb
drop back	No	No	Yes	No
hang back	No	No	Yes	No

As verbs, drop back and hang back are synonyms defined as:

Other synonyms of drop back include drag, drop behind, get behind, trail.

drop back (verb)	hang back (verb)
take position in the rear, as in a military formation or in the line of scrimmage in football	to lag or linger behind
to lag or linger behind