Phalanx on phalanx? I actually had a battle against some Carthage phalanxes yesterday. (played as Romani) My Hastati/Principes/Triari engaged them just fine. They had their pikes down and everything even after I encircled them.
Worked both fine on rtw/bi. But I noticed that the AI is MUCH better on BI, I get tons of naval invasions after I started playing campaign with BI.
If you're talking about a phalanx on phalanx I can't say that I've had one of those battles recently. : \