this is just you rationalizing a bad situation
the reality is that if we are aggressive in FA and draft will we can build this defense in 1 year.
The only way they can become big spenders in fa is if they can extend Dak and not have him playing on the tag. They could structure the contract to to hit more in later years. If he's under the tag again, there is zero wriggle room and they would have to restructure other deals to open up the necessary space. Team already restructure many deals to prepare for Dak's contract this season. Cooper's deal is the only obvious one they can restructure as they probably don't want to touch Zeke or Jaylon's deal as it would create a bigger hit if they decided to release them.
The other way to create cap money is to release players, but you would also create another hole to fill.
We also need to look at all the holes within the roster, as they like to cover themselves prior to the draft so in theory they can take the best player available and don't have to reach to fill a need:
Secondary-all they have is basically Diggs, Brown and Wilson under contract. They need to sign a few veterans to this positional group.
Linebacker-Lee/Thomas are fa's and they are moving back to the 4-3, they are going to need another starting linebacker and a quality backup due to Lve's health.
DL-Aldon Smith is a fa, they have nothing at 1T other then Woods.
Swing Tackle
Signing a 1 ticket free agent is wishful thinking and it's highly unlikely to happen.