Livy and Polybius - Biases?

[Johnny66]

I am interested in the 2nd Punic War and am interested to know if either source were sponsored by Roman families in order to make their military relative's memory look good for history (ie. the slain Consul Paulus at Cannae vs the ''aggressive'' surviving Varro)?

I understand that Polybius was a military man and wrote for the Scipio family, but what about Livy?