Take your expander plug out and see for yourself how long it is. Different brands and models are different. If this bike is as was originally new, then I'd expect that they put a plug in it that is long enough for you to remove spacers and put them on top or substitute similar width spacers if the profile of the lower spacers just looks too odd on top.

Or, you can cut the tube to what ever the proper length is. Just make sure you are certain where to cut. But when you do so, you won't ever be able to go higher if you later decide you don't like being that low.

You can find all sorts of contradictory information on the internet. Many times that's because different manufacturer's designs are different enough to require different ways to do things. So if you aren't looking at the instructions and manufacturer recommendations for that bike and it's fork/steerer tube if different manufacturer, then it's a toss up if you are finding information that applies specifically for your stuff.