What was subjective about Seb's career path Rasputin? That's what actually happened didn't it?
As for your suppositions, they don't really hold up to scrutiny.
was lucky to be there to take advantage of his world champion teammate falling out with the team
Was lucky the team chose to focus on him in only his second season
was lucky in his championship year that Alonso was in an uncompetive car and Kimi was on poor form.
Why did the double-WDC fall out with his team? Because he was getting beat.
Why did the team focus on him in 2008? Because it was more than obvious he was their only chance.
He beat Nando in the same car, why would he need him to be in an uncompetitive one?
And in actuality, I think it has become pretty obvious that 2007 didn't do Lewis any favors in the long run.
First off, his unbelievable entry into the sport created a legion of F1 watchers that would despise his every move for the totality of his career. Rookies aren't supposed to collect 9 podiums in their first 9 races you know!!! You're supposed to work your way up the ladder!!! I firmly believe his initial success is what has made people revel so heartily in his failures since then.
Second, despite his nearly impeccable driving for the vast majority of the season, 2007 is remembered as an abject failure by most people because of the single most delayed pit stop of all time, not to mention the 40 second "glitch" in his ECU. The often remarkable drives in his rookie campaign are largely ignored to this day.
Finally, Hamilton has yet to enjoy a single race in a car as dominant as the ones Vettel has been sat in for roughly 3/4 of his career. And I'm not sure its actually "lucky" to have your first car be the best car you ever drove. Seb's cars got progressively better as his career went along.
You couldn't have possibly laid down a better career path for Young Vettel. He's had every chance and every advantage. As far as I'm concerned there aren't any comparisons. And once again, this is not to say he's not a fantastic pilot, just extremely fortunate.