Its essentially irrelevant at this point but I want to address the idea that you need a top X player to win a championship. While having one of the best players in the league surrounded by other talent has been a recipe for success, there are teams that have proven exception to the rule.
Most recently, it was the San Antonio Spurs in 2013-14. There is no doubt that this squad was incredibly talented across their roster and had the best NBA coach of the modern era. However its worth noting thatnot one of their players was in the top twenty in the following categories: offensive rating, offensive win shares, or win shares overall. Nobody on their roster was top 10 in the following categories: WS/48, offensive BPM and VORP (as a side note, Duncan, Leonard and Green were all top defensive players). Duncan was already in decline while Leonard was in ascension. But neither was at a point where you would refer to them as, say, a top five player and maybe even arguably a top ten player that season - at least not statistically.
Next, I would argue the 2010-2011 Dallas Mavericks. Now this isn't to say Dirk Nowitzki of that season wasn't a very good player - he was. However he was already clearly in decline. If you look at metrics like BPM for the season, Dirk was 14th. If you prefer W/S, Dirk was 10th. VORP had Dirk at 18th. In fact, the only two stats where he was in the top ten was OWS where he was ninth and WS/48 where he was seventh. Instead that squad was a deep, well coached team that caught a break in facing the best player in the world with two sidekicks and not much else.
Before that I would cite the 2003-04 Detroit Pistons. Billups was very good offensively and Ben Wallace was the most dominant defensive big in the game. But that team did not have anywhere near a top five and arguably even a top ten overall talent on its roster.
The point is, the path to a ring isn't to have one of the top players in the world though that clearly helps. All of these teams were incredibly deep, had certain players with very elite skill sets, were all well coached and caught some breaks. In the case of the first three categories, I would argue that this year's Celtics are very similar - as to the latter category, while you cannot plan on catching breaks, its good to be prepared to take advantage. It would have been nice to see what the C's could have done with a George or Butler provided the cost wasn't gutting their current depth.