Exhaust Venting (help)

Need help with this one. Is the venting acceptable? I not sure were I picked up this narrative and looking for comments.

*** Safety *** the furnace exhaust flue pipe is not properly installed. The exhaust flue pipe shares a “T” connection with the water heater’s exhaust flue. Stand practices is the furnace having the higher BTU rating should have a larger exhaust flue pipe and be positioned below the hot water heater flue pipe where they both connect into a common chimney flue pipe. This is to prevent exhaust gas spillage through the hot water heater flue pipe and emitting CO into the home. Contact a licensed HVAC contractor to evaluate and repair.

The home also had a wood foundation and PB 2110 plumbing throughout. I’ll save those comments for another thread.

Looks like you said it though change stand to standard.
I can see backdrafting stains on the furnace side of the water heater hood.

Where is the support for the B vent by the way as that same hood is being pushed up ?

I don’t think I have ever seen a horizontal flue design like that. I would say your comment is warranted.