Actually they put a catch rate of 3 because the Beldum family was not intended to be catchable (it was given away as a gift by Steven in RSE)
Silly short-sighted asses >.>
On other Pokemon:
Deerling - Pretty meh. Doesn't deal much damage and is a pain to grind. He doesn't even have a grass STAB to fight Clay. Useless against Skyla and not of much use until Marlon. >.< Mid Tier
Roggenrola - Comes before the 3rd gym which it theoretically beats (but lolno leavanny). Ok against 4th gym but seriously wishes it's a ground type. Meh against 5th gym, decent against the 6th (lolswanna), meh against the 7th, lol against the last.
really nothing noteworthy throughout, but it has stealth rock which helps a bit... kinda. Mid