But "a lot more" is not a bounded heuristic. A good communicator would use more words to defend and idea than to present it, but way less than a bad communicator.

Defending rambling texts on the basis of "ideas take more words to defend them" is defending the incorrect idea that quantity is a quality in itself. Some ideas are self evident, some ideas can be defended in short well laid out arguments.

Even if a idea is complicated and requires a relatively long explanation. If that is the smallest possible defense, it would still be succinct even if the text is long.