You can or you cannot, if you are lucky enough that in 2021 most of the physics questions will be asked from Arihant book then you can score. But why you taking the case which has 0.1 chances to occur. I personally prefer take worst case scenario and practice as much as you can from both the books that you mentioned and if you still got time try more new books too. Because practice makes a man perfect, we can only do practice and the result is in almighty's hand. And all the best for 2021 exam.