Alright so I just did some quick statistical work regarding Johnathan Joseph and his partner over in Cincy, Leon Hall. Looking at both of them I think helps put things a little in perspective. Stats from nfl.com and
this place.
Joseph allowed 42 completions on 64 targets (66% completion rate).
Hall allowed 44 completions on 74 targets (59% completion rate).
Joseph's completions allowed represented 13.0% of the Bengals total allowed completions. His targets represented 12.5% of the QBs' total pass attempts.
Hall's completions allowed represented 13.6% of the Bengals total allowed completions. His targets represented 14.5% of the opposing QBs' total pass attempts.
Joseph gave up 436 yards or 10.4 yards per catch: 12.1% of total passing yards allowed.
Hall gave up 579 yards or 13.2 yards per catch: 16.1% of total passing yards allowed.
Bengals allowed 20 passing TDs of which 3 were attributed to Joseph and 5 for Hall.
Joseph had 3 INTs with 1 returned for a TD; Hall had 4 INTs.
Teams attempted roughly 511 passes (61%) against the Bengals as compared to 330 rushes (39%).
Not sure you can read TOO much into this without looking around the league for comparisons.