Awesome--I hope you receive them, and they are fine!

Don't fret too much over the legal aspects--many folks have to receive unmarked shipments every year and have done so without issue. USPS doesn't know what's in there, unless you tell them. There have been Lacey Act stings in the past, but it's extraordinarily unlikely that your little shipment would be among them.

It's not right, but that's the way it is.

As for 'mistakes'. A mistake is "Oops, I forgot to enclose that piece of paperwork!".
When you use a completely different shipper than you said you would, and lie about the contents of the package on the label, that is not a 'mistake'. That is a crime.