For those greenhouse coops we dug a trench around them. We extended the hardware cloth down into the ditch. We put drainage pipe in the ditch. Then we backfilled with river rock. That goes all the way around. (We also put a bed of sand inside the coops for extra drainage, just in case.) Then the planter boxes on the west side also discourage digging by larger predators on that side, the west side is the side with afternoon sun and strong evening breezes ... I'm thinking the boxes will serve as a wind break and block some of the heat during the warmest part of the day. Should help keep the coops comfy & cozy. Maybe. We'll see. I hope no raccoons use them as platforms to attack the roofs of the coops ... we haven't reinforced the roofs, though really you'd want some kind of wire there, too ... hardware cloth is expensive and we haven't had that problem yet, so haven't taken that step.
Right now it's summer so we have to mist the roofs when it's hot and sunny. We will plant more fruit trees in strategic spots for more complete summer shade. In the shade the coops are super comfortable.
The chunks of cattle panels on the ground work under a mobile cattle panel hoop coop with PVC frame we have. They can be moved relatively easily when we move the coop. Not something I'd want to do every day unless I had to. Also work in places you can't trench, like over major tree roots you don't want to disturb. Or along the side of a T-post anchored cattle panel coop. That's pretty effective to discourage digging if you don't leave gaps. Determined predators love gaps.
We have hawks, coyotes, owls, and raccoons/possums/skunks to worry about here. So far no fox or weasels or snakes or bears. This year chipmunks are getting my feed & eggs when the coop doors are open for the free-range bird. We found a cool trap for the squirrels. The larger predators seem discouraged by minimal fencing (lots of other options for food in the fields and woods). Hawk net protects the littles until they're up to size. Enough roosts inside the coop means the birds go to bed indoors where the owls don't hunt.
It seems to be as much about being responsive as it is about being prepared. No coop is going to be perfect.