Controlled Group - combined testing

I have a controlled group of companies - 2 separate plans.  The plans must be combined for coverage testing.  Unfortunately, they can't pass on their own due to the different sizes of the companies.  I know the plans cannot be combined if one is not a safe harbor plan and the other is.  Can the plans be combined for testing purposes if one of the plans provides for a safe harbor match and the other provides for a safe harbor non-elective contribution?  There are HCE's in each plan.  Thank you!

No.