I worked out at a site this last weekend planting trees, shrubs, groundcover and rocks.
I didn't know there could be so much work in putting in large rocks. digging the right shape of a hole for the rock you are putting in can be more time consuming than planting trees. If you want to put the rock in at an angle then you have to dig the angle into the ground before you set it.
At first I was told that we needed a trench so wide by so deep. This would have worked except that the rock they then selected had a nice growth on one side that they wanted to be more visible so the trench turned into what seems more like a truck loading area ramp so that it had a good viewing angle.
Then burying it took some doing while avioding ants which had been living where we wanted the rock to go.
Looking back I'm pretty sure it was well worth the changes.