Joseph will play at higher levels throughout his career and command higher transfer fees than both Beesley and CJ simply because he's much better than either with the ball at his feet. I can't really fathom why some are saying Joseph is poor, because his quality is obvious to me. Sure, he hasn't been scoring, but he has been contributing to goals. So have CJ and Beesley to be fair, but I'd argue that Joseph's better skill and closer control will make him more difficult to defend against when coming up against the better defenders.
I can certainly see why we were keen to sign him before he went to Swansea. If he stays fit, he'll prove a good signing.
There are some interesting stats on transfermkt that show that in league games only:
Joseph - played 1,071 minutes, 1 goals, 6 assists. A goal contribution every 153 minutes.
CJ - played 2,946 minutes, 4 goals, 8 assists. A goal contribution every 245 minutes.
Beesley - played 1,360 minutes, 6 goals, 1 assist. A goal contribution every 194 minutes.
It isn't a direct comparison because there are other considerations like the fact CJ has played wingback mostly, so you could say his scoring record is decent vs the other two. But Joseph has contributed well, and I think the goals will come.