Controlled group and safe harbor

Having a brain freeze ---- looking for confirmation or a directive to hit the books!

Controlled group with companies A, B and C. Client wants to adopt a safe harbor plan for A and B and not allow C to be a participating employer.

A has 7 HCE and 34 NHCE

B has 4 HCE and 17 NHCE

C has 7 HCE and 8 NHCE

Total is 18 HCE and 59 NHCE

A sponsors a plan and B signs participating employer agreement …. coverage is (51/59) / (11/18) = 141.45% coverage

Safe harbor is met with respect to A and B and we can forget about C as plan satisfies coverage so no ADP testing necessary.

Any 401(a)(4) testing for employer contributions would include the C employees with zeros, but probably fine since they have such a large number of HCE's.

Am I missing anything or misspeak somewhere?

Math looks fine to me.  I am assuming that C is not adopting any plan.

Correct --- C would have NO plan.

Since they aren't eligible to defer, no requirement to give them safe harbor contribution and A/B plan still satisfies the safe harbor.

Thanks for your confirmation.