As in "the defenders are as or better conditioned than the Offense these days? In JB's day, nearly all the best athletes were on Offense.
Now even the biggest baddest RBs can't survive...
Draft/sign a variety pack and when initial deal is done, move on... NEVER FALL IN LOVE !
Check out the HOFers... https://www.profootballhof.com/heroes-of-the-game/positions/
RB/QB (24)
Cliff Battles (HB) 1932-1937
Sammy Baugh (QB) 1937-1952
Tony Canadeo (HB) 1941-1944, 1946-1952
Earl Clark (QB) 1931-1932, 1934-1938
Jimmy Conzelman (QB) # 1920-1929
John Driscoll (QB) 1920-1929
Bill Dudley (HB) 1942, 1945-1951, 1953
Benny Friedman (QB) 1927-1934
Harold Grange (HB) 1925-1934
Joe Guyon (HB) 1919-1925, 1927
Arnie Herber (QB) 1930-1940, 1944-1945
Clarke Hinkle (FB) 1932-1941
Earl Lambeau (HB) # 1919-1929
Alphonse Leemans (HB-FB) 1936-1943
Sid Luckman (QB) 1939-1950
George McAfee (HB) 1940-1941, 1945-1950
John McNally (HB) 1925-1938
Bronko Nagurski (FB) 1930-1937, 1943
Ernie Nevers (FB) 1926-1927, 1929-1931
Clarence Parker (QB) 1937-141, 1945-1946
Fritz Pollard (HB) 1919-1926
Ken Strong (HB) 1929-1937, 1939, 1944-1947
Jim Thorpe (HB) 1915-1917, 1919-1926, 1928
Steve Van Buren (HB) 1944-1951
Purusing the list I linked to the 1st non-skill position inductee I see is an OT... Albert Glen Edwards (T) 1932-1940
Defender? Doug Atkins (DE) 1953-1969
QED...