I think he means "Why does the same 3.5L V6 rate as 269hp in the RAV4, 268hp in the Avalon & Camry, 270hp in the RX350 and 272hp in the ES350?"
I'd chalk up their slight variances to ECU programming, compression ratios and different transmissions.
We won't count the IS350, because we already know the dual direct injection pumps it up to a marvelous 306hp...