Laundry plumbing

[HappyCarpenter]

I found this done. I thought sinks could not enter below the laundry in the stack? Also, couldnt you use a double sanitee and eliminate the sink revent altogether? I’m sure this is an easy question for the plumbers. But I can’t seem to find these answers anywhere. I’m getting ready to put in a laundry room at my house so these answers would really help!