"identical with" vs. "identical to"

Solution 1:

To my (AmE) ear, identical to sounds better.

• These stones are optically, chemically and physically identical to natural, mined diamonds, but they suffer from a longstanding image problem. The New York Times
• Generic drugs are chemically identical to brand name drugs, equally effective and prescribed for the same purposes. The Chicago Tribune
• This difference is nearly identical to the 70 percent of non-white voters who supported the birth control mandate in 2012... The Washington Post
• The bill is identical to one that failed to pass the Senate by a single vote in November... The Boston Globe
• In fact, long sequences of dog mitochondrial DNA are similar or identical to those in gray wolves... The Atlantic

If it's good enough for the above, it should be good enough for your friend.