They want to build a team through the draft. So they sign players to 1 year prove it deals. And the players also may want that, it is not ALL on the FO.
Here is possibly why.
They sign a player, to fill a hole, stop gap type player. Draft BPA, and if that draft pick works out, they have that 1 year players replacement for 4 years. If the 1 year player works out they can offer him a better contact the next year.
Or.
If the player on the 1 year contract plays well, he can get a better longer term offer from Dallas, or another team. If that happens, and Dallas' draft pick works out. Dallas can get a possible comp pick.
So it has nothing to do with being cheap. They are trying to build a team for a 4 or 5 year run.
it is just they need an elite player to take them there. That is where they go wrong.