Parent onshore 804 Visa plus my Brother

I am writing to inquire about the possibility of including my 30-year-old brother, who has a mild intellectual disability, on my parents' 804 onshore visa application. I am currently planing to sponsor my parents to migrate to Australia on the subclass 804 visa, which is specifically designed for aged parents.
My brother has always been dependent on my parents for support and care. While he possesses basic living skills, he requires the presence and assistance of my parents to lead an independent life. It's important to note that he does not require any medical care or government financial support. Moreover, he is capable of performing simple labor-intensive jobs.
I wanted to inquire if there is a possibility for my brother to be granted a bridge visa with a work permit, allowing him to accompany my parents to Australia. This would provide him an opportunity to contribute to the Australian workforce and support himself financially. It would also enable him to continue living with our parents, ensuring his well-being and stability.
I would greatly appreciate any information or guidance you can provide regarding this matter. If there are specific visa options or pathways available for my brother to join my parents in Australia.
Are there any other options to bring him to Australia ?