Salem

i was wondering if plank fence can be destroyed and if it can how easy/hard is it to destroy

It can, like all walls it'll slow down any invader but they are useless on their own. A plank wall backed by properly set up braziers will keep invaders out almost guaranteed right now (Note this is probably going to change at some point.)

Plank walls don't take a lot more phlegm to start destroying than stones ones do, but they have significantly more HP. I reckon it takes 80' or above on phlegm to not do it at an agonizingly slow pace.

time to start building em lol

How do you set up braziers properly now?

Making sure they are not overlapping. Each brazier will hit base damage divided by amount of other braziers in its range.

(Their range can overlap, the actual brazier just shouldn't be in the range of another.)

so it would not be smart to try and just get as many braziers as possible then.

It wouldn't, no. You would probably end up dealing less damage than lower amounts.

You can place them in groups so you have X braziers dealing the damage of 1. This has the advantage of making it harder to decrease damage by spamming off-claim braziers in range. Other than that there is little to gain though.