[Rules] How does Modern handle friendly fire ?

[warstudent]

I hope this wasn't asked and answered already. I did do a search for friendly fire

When AP highlighted differences between PG and Modern PG it said:
Bombardment: Friendly fire is changed; no separate die roll on chart for column; use normal attack roll but receive a -1 column shift. Efficient artillery are better shots. http://www.avalanchepress.com/ModernSummary.php

Just curious if efficient artillery virtually eliminates friendly fire under perfect conditions? ie. weather/daylight/communication/