@wyatt1525 I think this depends on some factors like the weather, the size of your yard, and how much waste your pets leave (like two small dogs could be comparable to one medium sized dog, idk)
Anyway I have a similar situation. My spouse and I disagree on how much our 15 month old should be in our yard considering the pet waste back there.
We mitigate some risks by 1. Requiring shoes in the backyard 2. Dressing to mostly cover him so that if he falls down, his skin is covered and we can rest assured he's cleaner once dirty clothes are removed
3. Removing shoes, any dirty clothes, and immediately washing hands when we come inside
You can try all the tips to get your pets to go in the same spot and then avoid that spot, but I haven't been able to make that happen.