Pro Football Focus seems very impressed with the talent level of the Cleveland Browns players, and in fact, they compare favorably with the main Super Bowl contenders. Summary graphs are shown for the Browns, as well as New England (6 to 1), Kansas City (8 to 1) and the Los Angeles Rams (also 8-1), according to vegasinsider.com. The summary graphs are shown below if you want to skip the description of the math.
PFF keeps a huge database in which they claim every player is graded on every play. That database, though not infallible and not mainly intended for prediction of future performance, can be used to compare teams.