Here's an example of a walkthrough of sorts (excluding Accuracy Overflow as well as any other gear that buffs CrtH/CrtD)...

Base: 2.5%:50%; 1:20

+9WS: 4.5%:75%; 1:16.67

+T2 Rom: 7.5%:75%; 1:10

+T2 Dyson: 7.5%:85%; 1:11.33

+Rom Captain: 9%:88.8%; 1:9.87

+5x Sup Op: 19%:113.8%; 1:5.99

So we're at...

1 + (0.19 * 1.138) = 1.21622 or 121.622%

+CrtH Mod: 21%:113.8%; 1:5.420

vs.

+CrtD Mod: 19%:133.8%; 1:7.042

(CrtH) 1 + (0.21 * 1.138) = 1.23898 or 123.898%

vs.

(CrtD) 1 + (0.19 * 1.338) = 1.25422 or 125.422%

...or...

+ATVL: 20.6%;113.8%; 1:5.24

vs.

+ATVE: 19%;121.8%; 1:6.41

(ATVL): 1 + (0.206 * 1.138) = 1.234428 or 123.4428%

vs.

(ATVE): 1 + (0.19 * 1.218) = 1.23142 or 123.142%

There's a -1.524% difference in taking the CrtH instead of the CrtD.

There's a +0.3008% difference in taking the ATVL instead of the ATVE.

Now if they had the same ratio, say we start with 1:10...so we look at the ATVXs...

+ATVL: 20.6%;113.8%; 1:5.24

vs.

+ATVE: 19%;129.8%; 1:6.83

(ATVL): 1 + (0.206 * 1.138) = 1.234428 or 123.4428%

vs.

(ATVE): 1 + (0.19 * 1.298) = 1.24662 or 124.662%

Taking the ATVL would result in a loss just taking CrtH would.

If we look at the 1:5 and thus the CrtH/CrtD Mods...

+CrtH Mod: 21%:113.8%; 1:5.420

vs.

+CrtD Mod: 19%:123.8%; 1:6.52

(CrtH) 1 + (0.21 * 1.138) = 1.23898 or 123.898%

vs.

(CrtD) 1 + (0.19 * 1.238) = 1.23522 or 123.522%

Taking the CrtH would result in a gain just like taking the ATVL would.

With the ratios different...one does one thing while the other does another.