I don't think you understand the franchise tag.
I'm not advocating the amount the eagles paid Murray.
I recognize like everyone that RBs aren't worth much in the NFL anymore.
The cowboys reserved the franchise tag for Dez thinking they would be able to save money on his contract. They didn't, so they pissed away the franchise tag.
Dez got paid exactly what he would have without it.
Had they been smart, they would have given Murray the tag. He'd still be with the team at the appropriate pay scale. Dez would be with us at the same rate, and the line still intact.
So the choice comes down to this, which team do you pick considering both cost the same amount, financially equivalent:
1) Romo, Randle, Bryant and the line
2) Romo, Murray, Bryant and the line
I know which team I pick.
I encourage you to do a little Google research on the nfl franchise tag.