In your case, that’s working the opposite of how you might think. The F-111 started as two completely separate RFIs by the Air Force and the Navy. The Navy wanted a fast, high altitude interceptor with a massive radar to fire big missiles to kill Soviet ALCM carrying bombers. The Air Force wanted an ultra-long range supersonic low level fighter-bomber that could take off from CONUS, deliver weapons in Germany, land on un-paved strips, and do it again (Think the F-105 but T H I C). MacNamara saw “fast” and “fighter”, got a stiffy thinking about the Phantom, and decided they must be the same aircraft. The two services agreed on exactly two points: it should be swing wing and have two engines.
The Air Force made a big heavy boi that could carry oodles of bombs and fuel tanks and what not. Problem with that is generally speaking, the Navy requires specialized equipment to land on carriers, most noticeably bulkier landing gear, and the structural strengthening to support it. That takes a big heavy boi and makes it into a @klarsnow’s mom sized jet.
The F-111 wasn’t underpowered because the engines were bad (they were, but it would be 20 years until turbofans good/reliable enough existed), it was underpowered because it was a big, fat jet. It was never going to be a dog fighter, watch any interview with an F-111 crew for opinions/laugh tracks. It may have done alright as an interceptor, I don’t really know what it’s high altitude performance was. All of that is moot, however, if the jet is too fat to safely launch from or land on the ship.
The only reason the F-111B survived as long as it did while clearly being a terrible idea was that the SECDEF at the time thought he was the smartest, most unique person on the planet, and all those crusty admirals and generals were just jealous of his stunning intellect and good looks. In the process of trying to hammer square pegs into triangle holes, the other changes the Navy made to the F-111 (the squad, wide nose for example), irreversibly altered the USAF version of the F-111 to the point it would never be the aircraft it was envisioned to be.
The final jolly here is that in terms of economics, MacNamara’s ideas still didn’t make any damned sense. At most, the Navy “wanted” enough F-111Bs to equip their big top CVWs, or around 300. The USAF intended for the F-111 to replace most existing TACAIR aircraft at the time, or roughly 1,200 units. MacNamara dragged out the acquisition project, massively raising development and testing costs for an order that at most would be 1/5th the total delivery, and ended up amounting to a total of 7 units delivered. The economic ramifications from this meant a greatly reduced USAF order, leading to what you can considered an overall failure of the larger program when measured against it’s initial goals.
TL:DR, F-111B = Robert MacNamara =