I think that Benjy's strong suit is throwing in the call backs for Howard. Howard can't remember anything, so anytime he references a phrase or a story from earlier in the week or even earlier in the morning, methinks it is the work of the silent fat man.
Back in the day, Howard would have a pun-liner that would have been written by Jackie. Howard stopped using wordplay and old jokes when Jackie left the show.
I think Howard spends a lot of his day reading what Benjy writes. That's why he's so tired by the end of the day, he's clearly had enough.