Look at currently the Top 10 salaries of the Dallas Cowboys by position and by overall cap hit % of the team salary:
QB (Prescott) 14.47% or $31.5M
RB (Elliott) 5.01% or $10.9M
WR (Cooper) 5.51% or $12M
OL (Martin, Smith, Frederick, Collins) 20.88% or $45.47M
DE (Lawrence) 10.06% or $21.9M
DT (Crawford) 4.18% or $9.1M
ILB (Smith) 3.57% or $7.771M
So, as of today Dallas has committed 63.68% of the team salary for 10 players (7 on offense; 3 on defense) for a total of $138.641M. That right there is part of the reason they are where they are in terms of salary cap and player personnel.