all-embracing vs across-the-board

all-embracing and across-the-board both are adjectives.

Word	Noun	Adjective	Verb	Adverb
all-embracing	No	Yes	No	No
across-the-board	No	Yes	No	No

As adjectives, all-embracing and across-the-board are synonyms defined as:

Other synonyms of all-embracing include all-encompassing, all-inclusive, blanket, broad, encompassing, extensive, panoptic, wide.

all-embracing (adjective)	across-the-board (adjective)
broad in scope or content	broad in scope or content