The NFL is so dense with talent that the difference between a washout and contributor is often the slimmest of margins. Some of it is luck, some of it is circumstance, and some of it is skill. Whatever the case may be, contributors can come from anywhere.
Coming into 2018, few foresaw Antwaun Woods becoming a key cog in the Cowboys' defense, Joe Looney starting and performing competently throughout the season, or Blake Jarwin leading the Dallas tight ends in receiving yards and touchdowns, as each was a reserve when training camp began.
In 2019, there will undoubtedly be another crop of Cowboys players who surprise and become big contributors.