This is the general problem with deadline trades (holds for the NHL as well), if you're not good enough to win now, how many acquisitions can actually move the needle? So overpaying for maybe a 1 game regular season win and maybe one key AB or inning in the post-season is a good way to deep six a franchise if you do it on a regular basis.
Replacing a .700 OPS hitter with a .750 OPS hitter or a 4.00 ERA/FIP RP with a 3.50 ERA/FIP RP just isn't going to make much difference.
If you want to make a run, you're best bet is fixing Luzardo, maybe giving Ranger more rest, getting Nola back, bringing p Crawford and hoping Kempe will improve down the stretch with more PA. Long odds, but similar to those from 2nd tier acquisitions but no cost.