is this a rule that people follow? especially calculating the exact weight of things?

I'm preparing a session that rips most of the plot form this adventure and while I love the fact that the antagonists are smugglers in league with a merchant in the town, and that the villains are in a way proactive with setting up Ned's trap in the bedroom... I just don't buy this setup? Why would he need to pretend he was jumped? Why risk by getting him gagged and tied? What if nobody even enters the room?

It seems overcomplicated for what it needs to be and like... if they had the time and knowledge to set him up in the house- wouldn't they have the time to let the smugglers below know about the PCs and let them just set up an ambush the second they enter?

I still kind of want to use him in some way but the more I think about the situation the more unwieldy it becomes. Maybe he should enter the house a bit after the pcs have already explored it and pretend like something happened down the road to lead them into an actual ambush there? What if he volunteers to join them right there in town, claiming he was "good with the council" to lend any aid he can? Or find something they "claim to possibly still be there?"

I'm in a picke here.

I've glanced at equipment and made a small list of things I'd like to get, I haven't rolled the character yet, but I'm a sword and board type of player in my soul, so yeah any advice to give me an edge? I hope I can roll a paladin but I'm also feeling a fighter.