Unfortunately there is no alternative. In order to be relevant in a potential conflict with China around the first island chain, NGAD must have a size and fuel fraction similar to the F-111. It will probably also need a second crew position to manage the workload including controlling "loyal wingman" type disposable drones. There's just no way to do that on the cheap.

Small, cheap drones have been effective in Ukraine because the ranges are so short. The battle space in the South China Sea is completely different.