Yeah, basically dice calculators give you averages. With that info, you can opt for better choices for your army.
Using @Qark 's app, I've discovered that the E-5s 1R1W Critical 1 (the new "sniper" weapon for B1s) is better than E-5C 3B in the most important situations. Just looking at it without any calculations, I wouldn't be so certain of that!