Just to pick one player from your list, John David Crow...
He was one of SIX running backs in the 13-16 team NFL of the '60s to make the team. That would be akin to more than 12 RBs today making the all-decade team.
In the '60s, he only had one really great season, 1960. He led the league in yards per carry and yards from scrimmage, ranked 3rd in rushing yards and fifth in rushing touchdowns in the 13-team NFL. (He also led the league in fumbles that season)
In '62, he led the league in fumbles again, was 2nd in rushing TDs and ranked 8th in rushing yards. In '64, he ranked 10th in rushing yards in the 14-team NFL and fifth in rushing TDs. Crow was a good receiver (and even played TE his last season) but he only ranked in the top ten in one other season in yards from scrimmage (besides '60), and that was a 9th place finish in '65.
There was tough competition in the '60s for post-season awards with Brown and Taylor in the beginning of the decade and Sayers and Kelly in the second half. But Crow only made three PBs in the decade and was named a first-team All-Pro only once. As far as the HOF goes, his pre-1960 work doesn't do much to pad his case.
He's pretty obviously not a HOFer.
Brown, Taylor, Kelly and Sayers were obvious choices for the all-decade team. I've let my thoughts on Hornung be known before; Crowe was an okay choice for the sixth RB, but there were probably better choices for the 4th halfback position.
Timmy Brown for the Eagles had a more dominant stretch of play; Tom Matte may have been a better player, too. You could also have taken three fullbacks, and selected someone like John Henry Johnson or **** Bass or Don Perkins. The takeaway is that while someone like Crow was a really good player, no one thought he was one of the greatest running backs of all-time. He just happened to make the rather bloated all-decade team of the '60s.