Kinda like in 1954... when, during the competition for the USAF's first purpose-designed jet-powered tanker, they decided to buy a few "interim aircraft" and placed an order with Boeing for 29 KC-135s... and a few weeks later added 88 more to the order.
They then (in 1955) named Lockheed as winner of the contract (over the Boeing KC-135) and awarded funding for a prototype... and in the same statement announced they were ordering 169 more KC-135s "to hold us over until the Lockheed tanker is ready for production".
Eventually, the USAF canceled the Lockheed tanker altogether.
I can see the USAF awarding Boeing the contract, but ordering some KC-45As "as interim aircraft to hold us over until the Boeing tanker is ready for production"... and, as Boeing experiences the inevitable delays, ordering a few more... and a few more... and eventually canceling the Boeing contract.
The story of the Lockheed tanker is about 3/4 of the way down this article:
AmericanHeritage.com / Gas Stations in the Sky
They started with the CL-291 design, then went to the CL-321 design.
The KC-135 had 4xJ57 engines which produced 10,000 - 11,000 lb.s.t, while the CL-321 had 4xJ75s of 15,000 - 17,000 lb.s.t.
