Curious case of Warren Barguil. If he didn't win those two stages in Vuelta two years ago I would say he's one of the most overrated riders in peleton. But he did win those stages. And won Tour de l'Avenir (ahead of Chaves) few years back. And because of that he is considered as next French hope for GT win despite the fact that he won nothing in pro (apart from those Vuelta wins). If a guy who never finished in top10 in Tour is aiming top5 and already saying that in January and guy like Ten Dam is going to be his domestique it means that either he's so talented (not only in his opinion but also in Giant DS opinion) or.. they just don't have another rider to aim GC in Tour.
The fact is that he's behind Bardet and Pinot in terms of palmares. Being more specific I would say that they had much better results then Barguil at his age. The problem with Barguil is that he focus too much on one race, like Andy Schleck did before. He had a great Vuelta 2013, good Vuelta 2014 and pretty good Tour 2015. Apart from those three, he's almost invisible. I think he aimed too high in those first years. He should try aim for good results in one week races, try to win a race instead of aiming at GT all the time. Now it's too late because he's 24 and it's his last chance to win white jersey at the Tour so I have no doubts that he will again focus purely on French race. Yates brothers already passed him in terms of palmares. Meintjes is getting close. Soon guys from 93 like Latour might take his place as "next French hope". He really need to make a step forward and prove that he's a real GT contender.
Apart from all what I have said above, I believe in him

I think he's really a top talent but just lacking results. You have to be a talented guy to win two stages in your first GT. His win against Uran was a small masterpiece. The other win was perfectly timed attack. There was no luck in those wins. And let's not forget that he was aiming GC in that race but crashed in first week.
His 2014 Vuelta was also good. He was aiming GC and finished 8th. Good but not great but if you consider how strong was the first five and that Barguil finished sixth in the last mountain stage (behind the top five riders of the race) it shows that his level was really good there. And he was 23 that time. How many guys from 1993 will finish top10 in GT during 2016 season ? Probably none.
Finally the Tour 2015. He was in amazing shape right from the start. He's TT was bad but right from there he finished in first 25 places for next twelve stages ( the exception was Le Havre stage where Martin crashed and he was held behind, finished 75th). He survived the echelons, was attacking on cobbles and rode almost a perfect race before he crashed just before La Pierre-Saint-Martin. I think that was the reason he lacked a little in the final stages in Alps. Also, he said himself that he started Tour with too good shape and lacked a bit at the end. If he keep develops steadily I think his goal with top5 is quite possible (maybe actually top8 considering how strong Tour lineup will be) and white jersey is clearly in his reach.