While i agree with this and rather see coutinho playing as a cam or ss, he has played as a CM in the 2013/2014 season, when suarez, sturridge and sterling were making the front three, and he did well, really well for someone playing out of position. Good games specially against city and arsenal playing as a CM, there are complitations available.
I know that he is not a perfect replacement for iniesta because their styles are different, but still think coutino is a good player for barcelona, since he has the ability and mentality to link well with players like messi, neymar and suarez.
And about him being better than James and Isco, i really think this way because i've seen enough of their games. Coutinho only problem is consistence, but he is young and his team is inconsistent as well, so in a different team, in two years of experience, this flaw will be corrected.