So? If he summons the machines they won't be affected by Dragon Destroyer, and the machines will still be able to use their effects equipping the dragons to themselves.
I thought about commenting on Buster Blader not working well against it, too. But the more I think about it, it kinda makes sense. With a single Dragon in his Graveyard, it's bigger than any monster he could Summon aside from a Power Bond'd Cyberdark Dragon. That being said, Dark Paladin is straight better unless you fail to Summon it before Zane gets a Cyberdark Dragon.
Cannon and Claw wouldn't be able to activate their discard effect, meaning if this card is up on the field turn 1, Zane cannot get the dragons into the graveyard so they can be equipped, and cannot search Inferno either.
Yes, Cannon and Claw couldn't activate the effects, this is a good observation. But we all know that being able to summon this card on turn 1 is not that easy as it depends on luck. But this is a good card overall.