I'm using some large (a couple hundred pounds) boulders in our front foundation planting beds. These beds have a few inches of mulch in them, and my plan is to move the mulch out of the way and place the boulders on the soil surface, then move the mulch back around the boulder base. But I'm worried the boulders may over time settle several inches down into the soil and "shrink". Is it common practice, when placing large boulders like this, to perhaps pack down the soil where the boulder will be placed and put down a patio paver or two first, then set the boulder on the pavers to give it a solid base to set on and to largely prevent further settling?