pole horse vs draft horse

pole horse and draft horse both are nouns.

Word	Noun	Adjective	Verb	Adverb
pole horse	Yes	No	No	No
draft horse	Yes	No	No	No

As nouns, draft horse is a hypernym of pole horse; that is, draft horse is a word with a broader meaning than pole horse:

pole horse: a draft horse harnessed alongside the shaft or pole of a vehicle
draft horse: horse adapted for drawing heavy loads

Other hypernyms of pole horse include draught horse, dray horse.

pole horse (noun)	draft horse (noun)
a draft horse harnessed alongside the shaft or pole of a vehicle	horse adapted for drawing heavy loads
the horse having a starting position next to the inside rail in a harness race