Whereas no one will truly care in their crossovers (although I do), I think they need to rid themselves of using GM's parts bin shelf in their cars so they look like something special. I know it may be far more economical to use the 3.6L but since the CT5 is using the 3.0L their bigger car should take over where it leaves off. 3.0L and detuned 'Blackwing' should be CT6's only offerings when not in 'V' form.
#SideNote This does bring me to ponder what will be under the hood of the CT4. One engine in non-V? The 2.0L?