I love the idea of Dust just having a gun. I personally see Dust as a guy who fights far distance. And being forced into close combat, while not bad at it, it restricts him a lot. Even worse when it comes to hand to hand combat since he probably isn't physically strong. He's fast but not necessarily the strongest.
So, having a gun would cover his weakness.
And also to add more on how i believe the gang fights.
Horror would rarely strike first. He's probably more of a defensive player. He blocks blows and keeps the stars from getting close to Dust. It's hard to fight when someone(dust) is shooting blasters and bones at you. And being unable to knock that problem out when you're being continuously shoved further away by a brute with immense strength. (Horror can pack a PUNCH. I PROMISE YOU.)
Also because I believe that Horror, being the defense, matches my HC of his urge to protect and shield people. And not wanting to necessarily kill unless provoked or necessary. Horror is even given permission by Nightmare to not kill anyone unless deemed necessary for survival.
Now, onto how Killer fights. He'd prefer to fight in close combat, not necessarily hand to hand, though. Killer would struggle to fight far distance because of the issue with his vision. With the tears flowing out of his eyes, he'd struggle to see things from far away. Which can allow his target to escape if he struggles to spot where they are from a far. He also isn't very strategic with his blows. He'd be the opposite of Dust, who fights with strategy and logic. Killer fights with luck and opportunity. He prefers his fight to be fun without thinking or processing the possibility of failing. He also likes to confuse his victim, pulling out random jabs at them or teasing. His idea of a fight is excitement, not if it's life or death. He doesn't take fighting seriously unless he gets badly injured or someone else in the gang is almost ripped apart. Killers' unpredictability would give him an advantage in fighting. Since you don't know if he's willing to risk an arm of his own. Or yours. Also one more thing.. Killer, if not already fighting someone, he'd take on whoever Horror is dealing with. Ya know, making sure the defense isn't forced into the offense.
I fully believe that Nightmare has crazy strength in both physical and magical compartments. His preferred fighting tactic is close combat, and he'd only get into hand to hand combat when pissed off or forced into it by a stronger force. Far distance is when he doesn't necessarily take his victim seriously, that he doesn't have to get down there to fight them. Or that he's injured badly or too weak for his opponent at the moment.
Horror is the defense and also keeps people from getting to Dust.
Nightmare is able to fight no matter what. That old man can throw hands, trust 🙏
I wrote this down in case I wanted to draw it later. But also if you guys have your own personal ideas.. Let me know, I'd actually love to read how you guys think they fight as a team. 😼