I don't understand what you're talking about? Chikito was a skinny child froma poor family when he joined Ferre's band, he's now a teenager and it would be folly for anyone to expect him to have the same voice he had at 13 years of age when he made his debut on the single Lubukulukumu (Vita Imana remix), you cannot expect him to be skinny too when he's now enjoying his money.
These songs he's singing in the video you've posted above are originally sang by Ferre, he's improvising and singing Ferre's line with minimal error even when they don't have exactly the same vocal tone.
Look how young Chikito was when he started singing for Ferre
You honestly don't expect him to have the same voice now.
