Asokan, Thevar Magan is no way similar to Godfather... Nayakan is. It was unnecessary to force the comparison because Thevar Magan is a very original story... and brings out the psyche of the Thevar community, their heroism, violence and honor.
Your review otherwise reflected my opinion on the movie. It's one of the few films where every character has been well-conceived. And what a brilliant performance from all!!! Unfortunately, the director of this classic, Bharatan is no more. (He like many of his peers went unsung, largely due to the step-motherly attitude of the POP media (read Hindi dominated media) to regional movie makers. Thevar Magan is a great movie that deserves a hall of fame in the annals of Indian Films.
N Sharma