Those images in your post show doors made of multiple vertical planks. The planks can shift relative to each other, which is largely prevented by a diagonal compression brace.
Look at how a stick framed house is built. The plywood is typically all that is necessary to provide shear strength, as required by code. The plywood will not be the failure point of your door unless the wood becomes so compromised that it has no structural integrity. Keep it painted and you shouldn’t have anything to worry about.
Those images in your post show doors made of multiple vertical planks. The planks can shift relative to each other, which is largely prevented by a diagonal compression brace.
Look at how a stick framed house is built. The plywood is typically all that is necessary to provide shear strength, as required by code. The plywood will not be the failure point of your door unless the wood becomes so compromised that it has no structural integrity. Keep it painted and you shouldn’t have anything to worry about.