This is a double fixture fitting.
Even with these, the water can skip across.
I'm more inclined to not reinstall a cross fitting, but instead wye off lower in the wall and come up twice.
The two vents would then revent at 42" above the floor.
Here is a section of 3" copper pipe that I pulled out of a home in Somerset.
It was on a toilet waste line.
Helpful Plumbing Hints for Residential Construction by Bert Polk Plumbing Inspector Lincoln County