Both position-based and resource-based approaches are rational, which just means that you gather evidence from inside and outside the organisation and try to make rational decisions and plans based on that. Generally rational planning tends to be thought of as long term such as 5 years rather as opposed to the shorter term logical incrementalism or opportunistic approaches.
Where the resource based and position based approaches differ is in how they respond to change. The position based approach says that the company must alter its position (ie what it does) to match the environment. That could mean abandoning its current resources and competences and finding others that march the environment. However, that might not be easy as those resources and competences could have taken decades to acquire.
The resource based approach says that the company should not panic and should not be so eager to abandon resources and strategies. It asks the company to try to imagine what else it could use its powerful, valuable resources and competencies for.
HTH
Where the resource based and position based approaches differ is in how they respond to change. The position based approach says that the company must alter its position (ie what it does) to match the environment. That could mean abandoning its current resources and competences and finding others that march the environment. However, that might not be easy as those resources and competences could have taken decades to acquire.
The resource based approach says that the company should not panic and should not be so eager to abandon resources and strategies. It asks the company to try to imagine what else it could use its powerful, valuable resources and competencies for.
HTH