dwv horizontal vent

Hi all, love this forum! Has been a huge help getting me closer to passing inspection as an owner-contractor updating in IPC country. Ok, so in this initial layout (image) A) I tried a rolled wye above centerline for dry venting the toilet and shower only to learn on inspection that dry vent...

When plumbing two showers, can I connect vents together, running horizontally over a door or window instead of running two roof penetrations? The total separation distance of the drains are ~6ft (but could be reduced slightly) & there's not another vent within 5ft so they have to have one...

I have searched the web and forums trying to find an answer for this on my own without any luck. I'm in the middle of building a new house and am starting on finishing the plumbing rough in before we start insulating. My rough sketch should give you guys an idea of what I'm asking. We roughed in...