You aren't looking at this from a cost perspective.
You have windows for success in the NFL (largely).
I would suggest that Zeke is our best player right now. You have him for 3 more years and then his cost becomes prohibitive, especially in this offense.
That suggests to me that we have a 3 year window for success.
Within that 3 year window you have smaller windows, such as Dez Bryant who has 2 years left on contract and it isn't even financially wise to keep him at the moment. He should be cut.
You look at Tyron and he is not going to get better. You have him for a long period of time, but the outlook isn't great. I would trade him while you can.
The team is not just 3 players. This team is rebuilt, sure it needs some more players but everything is in place. Young OL..... Tyron isn't old just needs to work out his injuries but with Frederick, Martin and Collins they are in place to add too. 2 very young QBs, young RB plus a young backup with Rod. DL is young, LB has an aging Lee but some young pieces as well. Secondary just got a make over.
In my opinion the receiving corps needs more options but we do have Switzer and Brown. TE with Witten is the oldest.
So keep adding LB, OL, WR and LB. The window is wide open, it's not closing. The main problem is coaching overall