For the size of the Arena, not sure it will help necessarily, but the Greek and Roman stadion/stadium, also known in English as the stade, unit of length was around 180-185 metres in length (there were variants, and some modern estimates have varied still further from this). That might be a way to go, though it would be likely the inner circumference, not the actual length of the construction in an oval form. It really depends what goes on there as to how large it should be.

The River Docks is another in the "length of string" debates, as it depends what the river is used for and by what proportion of the populace, whether it's used for exports and imports (and what of, type and quantities), does a ferry run from here to other places (such as even across the river), etc., etc. To my eye, for a river of this size, the three docks now seem probably too few, but more information would be needed for a more definitive answer, I think.

So this would be the Better Day At Blackrock, presumably ?

Impressed that you've managed to "force" @Loopysue to reveal her hidden treasure in the City Cliffs Annual @Elfling!

I understand what you mean about how parts of the Tome and help files are sometimes written. It can be frustrating when you know what you want to do in CC3+, but can't quickly find the information on how to do it. It's often a matter of experience, trial and error (lots of the latter, in my case...), and taking time to watch through the video tutorials (the Joe Sweeney ones are what most helped me when I was trying to first get to grips with the program some years ago, though there are plenty more now by other folks too), and/or reading the written tutorials, if that's more suitable for you.

Sue's right I think in suggesting the Symbols Along command might work nicely for your palisade fencing. You may already have access to suitable symbols from what you have installed for CC3+ that will let you do this without needing to create fresh ones too.

You might want to think about the Symbols in Area command as well, which allows you to fill a polygon of whatever size and shape you wish with your selected symbols - a narrow strip polygon could work for things like hedge-lines made up of individual bush and tree symbols, for instance.

I suppose I'm just more used to having worked with real scrolls down the years, than how cartographer's have opted to draw them!

That's 497 maps now, according to the Downloads page in the Atlas!