^ What Sachin did worked for him and his style of play. He also held the bat very low leaving top 3-4 inches of the handle untouched. He played against some very quick bowlers. Since pro grounds have quick outfields, you don't need to swing the bat hard. A well timed push from a heavy bat will do the job and send the ball racing to the rope. We all know that he was a kid, he used his big brother's bats which ultimately led to certainly physiological strengths. So, he preferred big, heavy bats. Check out the bat he used in 2011 CWC, it was huge!
Regardless of what Sachin or others did, bat weight preference is subjective. If you want to find out what works best for you, try different styles and weights of bats and see which one produces runs for you. Without standardizing bat specs (dead weight, swing weight, point-of-balance, willow density, etc. etc.), there will be never be an exact process for determining or replicating the right bat for a batsman except trial-and-error.