I agree with Vern. You need to push back to your Client showing them that it is not required. I'm the SBLO at one of those "large aerospace companies", and even we get it wrong sometimes. Most of the time, it is due to the buyers not running the small business requirements by me. Therefore, they are flowing down requirements that don't need to be and/or using proposal instructions from other projects where it may have been applicable. If, after letting your Client know the subcontracting plan isn't applicable, and they still tell you it is, it is possible that they deemed the procurement non-commercial. You may need to assist them in showing that the procurement is indeed commercial.
No matter the case, if you feel something isn't applicable, let your Client know and even request to speak to the SBLO directly if needed. Just be prepared with references as not all SBLOs fully understand the requirements themselves.