Prevention of future stroke. 150 mg ) ?

My father had 2 ischemic stroke. In 2020 he had stroke in PCA territory. At that time Aspirin 75 MG along with Atrovastin 20 MG was started. After that, in 2022 he faced another lacunar stroke. After that the dosage of Aspirin was increased to 150 MG. And rest of the medicines were kept same. Now , my question is how can we prevent any more stroke in future ? Can you tell whether single antiplatelet therapy is good for prevention of future stroke ? Or dual antiplatelet therapy ( Aspirin 75 MG + Clopidogrel 75 MG) is a better choice than single antiplatelet therapy (Aspirin 150 MG ) ? Please share your suggestion from your clinical experience. For any change in medicine we shall take Physical Consultation from the Neurologist who was treating.