no he doesnt. Carlos even zei in an interview "what makes this band unique from other boybands is that we all sing lead. There are no back-up singers."
Standing ovation for that remark. They've just ended season one here and God knows when they are going to air season two and release the new album. It's hard for me to judge. But I noticed that throughout a song that the lead changes. Not to forget that everybody has always a 'different' position in a song, so everything 'balances' out.