Not if you’re going against the Taliban or Al Qaeda. The exception would be shoulder fired SAMS, but those are likely older versions that we have good CM for. And against those targets, they probably won’t even know you’re there until things blow up real good.
The problem is that we may not always be going up against an enemy that doesn't have an Air Force. It takes years to spin up a production line for a fighter aircraft. Once the aircraft reaches early production, you need to develop tactics to take advantage of the aircraft's capabilities. Once you have the first few airplanes and have initial tactics you need to train pilots. The pilot training pipeline for the F-15 was two years long - about eight months of that was in the F-15. That got you a minimally qualified wingman. It took at least another year to qualify him as a flight lead.
We need to have the aircraft in the inventory and have trained pilots at the beginning of any hostilities.