Adding a stopper knot after the Noose Knot is a must. It isn't optional and isn't just for 'extra security'. Without the stopper knot, the Noose Knot can slip
a lot and can even completely untie itself. I'm not saying that it always will, but it can, depending on the type of rope and other factors. It's not a good idea to take that risk.
Here are two videos to illustrate this.
In the following video, I tied a Noose Knot without a stopper knot and pulled on it. I think the video speaks for itself, and it's clear that the knot isn't secure.
In the next video, I tied a Noose Knot around an object that doesn't have a smooth surface. The video shows that the Noose Knot can slip and roll around the object. This can easily happen during hanging if someone doesn't tie a stopper knot in the tail end.
There is a reason why the
Arbor Knot or the
Canadian Jam Knot are tied with an additional stopper knot. Omitting the stopper knot is a critical mistake.
@ratherpainful, Evelyn's guide doesn't mention it, but I don't see that as a counterargument. She doesn't address this problem either way. She might have simply not thought about this, who knows. If you think my explanation – including what I said in the
comment you replied to – is wrong, then please point out why. But if you just say that it isn't in Evelyn's guide, I don't know how to respond to that. Regarding hanging videos, people do all kinds of things in those videos, so I don't see how this is relevant either. Besides, I'm not sure how you can see what exact knots are used in those videos, because it's impossible to see most of the time
Technically, the Arbor Knot might be slightly inferior in terms of strength, but this is theoretical and doesn't really matter for us. First, I'm not even sure whether there is a meaningful difference in strength. Second, if you use the Arbor Knot at the neck side anyway, then it doesn't matter whether there is another one at the anchor side. Two Arbor Knots is not weaker than one. And an Anchor Hitch on one side and an Arbor Knot on the other side is not stronger than using Arbor Knots on both sides. Your overall setup is only as strong as its weakest point.
Think of it like this: You're worried whether the Arbor Knot is robust enough to use. So, instead of using the Arbor Knot, you wrap your rope around the anchor point 100 times, tie 50 Half Hitches around the standing end, and you finish it with 37 stopper knots. That's quite secure. Okay, but there is still an Arbor Knot around your neck! So did you really make your setup more secure? (No, you didn't.)
Practically speaking, whether you use the Arbor Knot, the Anchor Hitch, or another knot at the anchor side just comes down to personal preference. Use whichever one you feel comfortable with. It's absolutely fine to use the Anchor Hitch. But if you use the Arbor Knot for your anchor point, you're not making a mistake either.