That's a good point. IMO the amount of overtakes in 2010 is artificially increased by the three slow new teams, because if a driver from an established team hits trouble early in the race, he can easily get 6 scalps sooner or later. And regardless of the toughness of overtaking in modern F1, the new teams are too slow to have much chance of holding anyone up long-term. I think partly that's how we got 21 (?!) overtakes in Bahrain. Wasn't it Hülkenberg, who dropped to the back in the beginning before starting to overtake cars from new teams?