"Praying for the best" did not turn out to not be a winning strategy this time.
We managed to arrive in Amsterdam without a single delay, but our bags did not.
Things got off to a bad start when the check-in agents in Lusaka tried to charge us $590 for overweight bags (a dubious claim, since they somehow got much heavier between being weighed at the office and arriving at the airport). Then the agents offered to help us sort out the manner if I could give them "a little something to buy drinks."
When they mocked the size of my bribe, I knew we were in trouble. But I could not have guessed that "trouble" would mean they seemingly did not check in our bags at all. All four have completely disappeared from the airline's computer system, though we have the claim tickets.
Well, the silver lining is that, as noted above, Trevor finally has a legitimate excuse to share my underwear. (Though we bought him a new set of clothes-- including undies-- on the way to the hotel.)
And in our frenzy to collude with the gate agents and make it look like we were making our bags lighter, we threw a ton of stuff from our checked bags into our carry-ons, so we have a bunch of things that would otherwise be lost now. And my carry-on contains the clothes I planned to wear on the holiday, so even though Trevor landed with nothing but a toothbrush and sandals, it could be worse. We have money, so I think we'll manage somehow.