Help Needed: DWV layout

Please take a look at my proposed DWV plan for two back-to-back bathrooms and let me know if I am on the right track...

First picture is the top down view and the second is my best attempt at an isometric.

Key questions:
- is the venting correct?
- are there enough cleanouts and are they in the right place?
- do I have the right connections from the trap arms to the drain? (I see tons of pix online for vertical to horizontal connections, but very few from horizontal to horizontal).

Thanks in advance -- I greatly appreciate the help!

What code do you use in WASH. codes vary place to place

Here, every trap requires a vent.
The tub ,shower and toilets all require a vent.
Vents can connect above flood rim of highest fixture.

What is below the floor? crawl space, slab, basement.
How much room below floor joist can you drop the drain.
You can use one vent for both toilets if you use a double fixture tee.

Okay see if this makes any since.

Mr. Dave,

Thank you so much for your quick and detailed responses! Washington state operates under UPC code, so I was hoping to do wet venting where possible.

The wet wall is only 2"x4" and there is no attic (old ranch house with low vaulted ceilings), so I am hoping not to have to drill 2"+ holes through three consecutive studs.

The bathrooms are located over a basement which has only 7'2" ceilings (ugh...'60's construction!). Because of this, I am trying to save on altitude as much as possible. And, of course, the floor joists (thankfully 2"x10") run perpendicular to the wet wall.

For that reason, I was trying to make horizontal to horizontal connections instead of the vertical to horizontal connections your drawings show. Is there a code &/or functional reason for not installing the DWV that way?

Thanks,
Les