No. He is an "articulate" speaker tells us that he expresses his ideas "articulately" or with good word choices.
He is a "concise" speaker tells us that he expresses his ideas "concisely" or without any unnecessary words.
As you can see, the two ideas are similar without being identical. People can speak concisely without speaking articulately. People can speak articulately without speaking concisely, especially if they like to talk a lot.