Tata is also a better coach than Sabella. He also knows perfectly how to fully use Messi's game.
Disagree. Sabella was/is a more accomplished manager. Having won the CLi, his Estudiantes gave Pep's Barca a run for their money in the CWC not so long ago. He took over ARG at a difficult juncture, and built the team from scratch. He was initially stubborn but he got a lot of it right eventually. Messi never had a more productive period for ARG like he did under Sabella, whilst ARG as a whole became a more well knit and organised group under him. His attacking force let him down during the WC proper, either due to lack of form or fitness., forcing him to employ a more pragmatic approach. People question his choice of personnel, but given a lot of the new/recent flavor were not a factor or consistent a year or so ago, it was only logical to operate with the squad that sweat to qualify for the big one.
Sabella's the man behind ARG's resurgence, the man who's laid the ground work for Martino to reap the rewards. Martino may go on to win whatever titles. Sabella > Martino. Always.