Sorry for the misunderstanding re. Aigle, I meant physiological potential of course. To become a GT contender you clearly need far more than just the basic physiological tools for the job, some of the other tools such as endurance, patience and recovery you will only identify and develop over time.
From the same Procycling article there are another two relevant quotes which may add to this discussion,
WCC Coach Michel Theze at 2007 Giro delle Regioni on Froome (he was competing for WCC) "When it's tough, he's very strong - better than the rest, but he's not a technical rider yet. He fell four times during the race. Two of his falls came in the third stage costing him 1:20. When you see that in the final ranking he is only 1:25 behind the winner it isn't difficult to do the maths..."
Claudio Corti somewhat famously announced before Froome's TdF debut that he would "finish in the top five of the Tour de France or do even better." although I presume he didn't actually mean he would do this on his debut.
Daniel Friebe adds that no-one paid any attention, but they did interview him on the night before his tour debut. "Froome's mother had died of cancer two months earlier and, what with the grief, his inexperience, the callow impression he made on us that day and his coach saying that he had barely touched his bike for weeks after his mum's death, we expected him to last a few days. Instead in the final week of the race he was climbing with the leaders on L'Alpe d'Huez and finishing 14th in the time trial."
There's also another good quote from Bobby J about 2011, (same caveat as above I suppose re. hindsight.) "We did some lab testing with him early in the year and it wasn't making sense. I saw the numbers and said to Rod that the machine must be calibrated wrong, because these were the numbers of a guy who would finish on the Tour de France podium. Rod told me that, no, they were right. I was amazed."
So if you add the three unrelated observations together, that he had the 'numbers' to get on the podium, that even with a compromised lead up with his mum's death he had the endurance and recovery to not only finish his debut tour but finish it comparitively strongly and that from two different sources we have criticism of him technically at a level which certainly backs up the fact that he was losing races and by relatively big margins because of his lack of skills. (The zigzag video is another perfect example of this, as is the collision with the commissaire in the worlds. Honestly, he was a bit of a menace

)