Since those shadows are basically undead ghosts, Jinwoo being the necromancer, they are all his slaves, to put it bluntly. He should never have any trouble controlling them, regardless of what they thought of him while alive. However, we have already seen Iron do some stupid stunts as a shadow, just like he was stupid in life. The stunts are just somewhat different since as a necromancer's summon, he will be forever loyal and thus any disobedience won't play a role. That doesn't mean the shadows wouldn't do things on their own to varying degrees, probably dictated by the power level in life, which seems to lead to higher intelligence as a shadow. And any personality quirks.