I’ve been extremely lucky but I just have a chain link dog kennel run for my run and I’ve been meaning to put hardware cloth up around it but haven’t but have been lucky. I did put wire around part of it though and there is a heavy wire skirt along the edge that butts up to the woods. Before that I had railroad ties on one side (it was in a different spot until last year). Anyway, I’ve had it 4 years and it’s worked for me and we have had fox and raccoons try to get in. Had some hawk attacks while free ranging, lost one, but otherwise fine. I do have 2x4 type welded wire on top, it’s coated in green vinyl, and it’s worked well. Before that it was just deer/bird netting to stop them from escaping but that stuff was a huge pain in the rear so I switched to the welded wire. I just zip tied it together and to the top. It’s worked really well. I’ve even had foxes and raccoons climb/jump on top of it and walk on it and it’s held up to their weight. So I’d say it works. HC is expensive and I’m not sure if I’d use it on the top of the run or not. Not really necessary. But if you want to be completely sure no predators or pests can get in then I would. Depends on your personal preference. But we are on 2.5 acres on the south shore and have a lot of trees/woods so we have everything from deer, turkeys, rabbits, squirrels, to coyotes, fox, hawks, raccoons, etc. think we have skunks too and of course we have a major chipmunk problem atm that we are trying to deal with. And I have had chipmunks and squirrels go in the run to eat the food, currently the biggest issue is the chipmunks, but I moved the food bowl inside the coop and have not had an issue since. Also mine don’t even try to fight them. They just run away and/or watch them eat their food. So I wouldn’t worry too much about guts but depends on your chickens I guess. Anyway, I think welded wire would be fine.