Clearly you did not watch the games this year.
The games where we passed early, on early downs, we scored points and built leads, and ran effectively in the second half. Pass first does not mean passing 40 times a game. Our offense was the most successful when we ran it 40% or less in the first half.
When we did what you suggest, we fell behind, and HAD TO PASS MORE. Passing early will actually lead to passing LESS.
Not sure what games you were watching. Here are the last 8 games of 2019:
MIN first half - Passed 23 times, ran 13 times (36.11%): Dak ended with 46 attempts. Losing at half and we lost 24-28
DET first half - Passed 25 times, ran 13 times (34.2%): Dak ended with 46 attempts. Winning at half and won 35-27
NE first half - Passed 12 times, ran 17 times (58.6%) - During our two first half scores we ran the ball 12 times (to 4 passes). The rest of the half was 8 passes and 5 runs (38.4): Dak ended with 33 attempts. Losing at the half, lost 9-13.
BUF first half - Passed 21 times, ran 15 times (41.6%) : Dak ended with 49 attempts. Losing at the half and lost 15-26
CHI first half - Passed 15 times, ran 16 times (51.6%) - we ran the ball 10 times on our first drive (to 2 passes) leading to our only score of the first half... After that drive: 13 passes, 6 runs (36.1%): Dak ended up with 49 attempts. Losing at half and lost 24-31
LAR first half - Passed 16 times, ran 24 times (60%): Dak ended up with 23 attempts. Winning at the half and won 44-21
PHI first half - Passed 18 times, ran 6 times (25%): Dak ended up with 44 attempts. Losing at the half and lost 9-17
WAS first half - Passed 17 times, ran 17 times (50%): Dak ended up with 33 attempts. Winning at the half and won 47-16.
With the exception of the Detroit game, the exact opposite of what you said happened. Each game we were around or below 40% running in the first half we ended the half down. We scored a TD against the Bears by running the ball on the first drive 10 times, then basically abandoned the run (6 more rushing attempts the rest of the half). Our two scores against NE in the first half were on predominantly rushing oriented drives and passed more than 60% on the stalled drives.
The games we won against the Rams and the Commanders our run-to-pass ratio was at least 50% and both of those ended in blow outs.
We lost to most of those teams because we either abandoned the run or just decided to pass more than 60% of the time in the first half. This directly led to Dak having to pass more in the 2nd half. All of the games listed where Dak threw 40 or more attempts we actually rushed less than 40% in the first half. Passing early didn't lead to less passes it actually led to more compared to the games where we were more balanced.
Keep in mind I am not blaming Dak. Far from it. But we are better when we are balanced or leaning towards rushing. The results from the 2nd half of the season show that when we became pass happy and abandon the run (for whatever reason) it usually put us in a hole at the half.