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.

I'm just another poster on the forums with my own ideas and opinions.