Blast protection of doors and doorways

So I was browsing the Rust Wiki and I noticed the amount of blasts needed per base item:

Wooden doorway : No blast amount stated.

Wooden door :

500HP

2HP per Rock - 250 Hits
1HP per Stone Hatchet - 500 Hits
2HP per Hatchet - 250 Hits
6HP per Pickaxe - 84 Hits
600HP per Explosive Charge Explosion - 1 Hits

Metal doorway : No blast amount stated.

Metal door : 11-13 F1 Grenades , or 2 explosive charges (usually taking two due to decay)

Now its pretty obvious that a metal doorway + metal door provide better protection that a wooden doorway + wooden door. But what if you do a wooden doorway + metal door, or metal doorway + wooden door. Does this affect its resistance in any way, or does it take the resistance of a specific item, or does it take the resistance of the strongest item?

So basically what I've learned is that a wall-section (window, door, wall, etc.) is as strong as the weakest part of the section. So for example if you build metal window bars and place them in a wooden window (frame), the section would be as strong as the wooden window since that is the weakest link. So to return to my original question, let's say we place a metal door in a wooden doorway (which happens quite often), would you be able to blow up the wooden doorway without destroying the metal door? If so, would destroying the wooden doorway grant you access to the base (or building/wall/etc)? The same could be asked for a window.

The wooden door would have the same health in a metal doorway as it would a wooden one, taking only a single charge or numerous attacks from various equipment to break. Each individual item's health is its own health, completely unaffected by its surroundings.

Destroying an object that is supporting another object will cause the supported object to be destroyed as well. A door cannot be placed without a doorway, a doorway/wall cannot be placed without 2 connecting pillars, window bars need windows and so on. Destroying something that would render the conjoined objects unsupported will destroy them.