The main problem with the AI is that there isn't a sensible default. "Challenging" Cassandra Classic is the baseline, but it's ridiculously hard. It goes something like, start with 3 guys and face 1 raider a couple times, then you have 5 colonists and managed to make 5 wooden rooms, and the next wave will be like 7 pirates with pistols and rifles.
If you manage to have something like a decent colony with 5-6 people, some lee-enfields, decent food facilities and workbenches, lighting etc, we're talking about waves of 15 raiders with power armor and miniguns every 3 days.
Phoebe builder's frequency is about right, otherwise you just can't ever get anything done. I'm going to try it on "Rough" to see if at 60% the regular attack force it's something more playable.
I've found the best, most efficient way to find the edges of a Rich Soil is to fill the whole area with conduits, they prevent growing of grass and you can easily deconstruct the parts that have regular soil and get all your metal back, then once you got the area figured out you can place the growing zone. It's a bit cheaty in a way because it removes plants SUPER fast (even trees), on the other hand make sure to chop and harvest before you start covering, but even if this gets "fixed" and colonists have to actually spend time removing the grass it's a major time (and sanity) saver.