From what I have been able to gather, Chhatrapati Shahuji, the fourth Maratha Emperor, did not have any sons from his own body and instead adopted two sons. It is my own belief from what I've read that the fact that his adopted sons were not nearly as capable as him that led to the growth in power of the Peshwa's. What my premise is, is that the man manages to father a legitimate son on one of his wives, and manages to raise a son let's call him Shivaji, who turns out as determined as his namesake, and as capable.
What might the consequences of this be?