Split plans to avoid audit - with a twist

Plan sponsor wants to split its current SH401(k) (130-ish participants and going up each year)  into two identical plans in order to avoid the audit requirement.  Split could probably be done by placing certain categories of EEs in just one plan.  I'm much more comfortable with this than alphabetical approach, but my understanding is that is that even that is generally considered acceptable.

Here is the wrinkle.  There is also a cash balance plan that is tested with the DC plan.  Does this make splitting the DC plan more complicated?  I had a brief conversation with an actuary and even he was stumped and needed to do some digging. 

Any insight would be greatly appreciated.

I'd be surprised if it turns out to be an issue.

Thanks Mike

Just permissively aggregating 3 plans instead of 2, right?

Correct.

Thanks guys.  The actuary got back to me as well and came to the same conclusion.