what do you mean critical or 2 hits when they unite? i don't think that's possible for unites
I'm positive that it counts in unite here, may be you mix up your memory with S3 or S2.
Although i can't really provide any proof that was a critical hit or 2 or 3 multi hits but I use unite frequently so i notice this.
For exemple: normally sworn protector with optimized miakis point will deal 4.4-4.5k on sunri but when the "hyper chance" kicks in it could deal 8k to 9999 , other than an explanation from critical and multi hits also count, i can't understand that then.
you can take a look at this video, *just forward to the final boss part*http://youtu.be/O386i8K9xLA
without the "hyper chance" sworn protector should output 4.5k, armes greeting 3.7k and maximilian should deals just 6k. but i often see this kinda thing happen that's how i concluded critical/multi hits performance of each individual occurs and get counted.