Which is better strategy to learn and read books, traditionally one by one OR re-read carefully on perfect books

You are right. Our time and energy are limited and it is logical to use them in the best manner possible. But reading the "Masters" isn't always the right way to learn mathematics. They may have been masters in their field but that doesn't mean that their books are the best possible books for you.

For example, some years ago I tried to read Hardy's classic book on Number Theory, but unfortunately at that time I felt that the book to be a very dull one, either because I didn't understand it or because it really was dull! However, having read some other "Intro" books on Number Theory, now I don't find that book so much dull as before.

However, there are some things that may be learnt directly from Masters. For example, I found it especially helpful to read Landau's classical text Foundations of Analysis for a rigorous understanding of Analysis. Russell's Books also helped me to clarify my concepts about the logical foundations of mathematical principles.

One word of warning (perhaps out of the place, but still important), DON'T TRY TO IMITATE THE MASTERS. It's okay if you can't learn from Masters but it will be a mess if you ruin your natural genius trying to imitate them.