I'm more under the impression that there are several people who tweet using that account (you'll remember one of his lawyers claiming they did one time he really screwed up) using different platforms
I can't find the link on mobile right now, but there was an article I read a while back (on HN, actually, I think) where someone did statistical analysis on the speech patterns of Trumps tweets and correlated those with times he was known to have been using his phone (or something like that) and deduced that there were two primary parties responsible for his Twitter account: Trump himself and a PR person/team. Any politically-minded (in the classical sense) or campaign tweet was almost always by the PR team, and every inflammatory, grammatically incorrect, etc. tweet was by him (presumably).
I was thinking of the same article, and found it, I think [1]? There was a higher-rated link also posted around the same time with the same post content [2]. I also found a follow up post [3] while looking for [1].
