Thankfully you're not a filmmaker.
"Your petty vengeance fetish will have to do withOUT Mr. Groin!"

I don't care how short they make the movie as long as they don't edit out Ghost Boy.

So you just add another couple minutes where they get the bad guys. That's what they did anyway in the actual movie

Well if you had actually been paying attention, you would have heard Jack calling Peter and Michael to tell them that a package was being delivered that day. The package in question was from his friend Paul Milner and, unknown to Jack, it was drugs to give to those dealers. But then, by sheer coincidence, a baby is left on their doorstep and the note is from a woman Jack banged a year ago and this was their lovechild. Since the mother was obviously leaving the child for Jack, Peter and Michael took it upon themselves to hold on to her for him. The baby wasn't just randomly left at their door, and they knew who it belonged to.