From a discussion I had with a good friend of mine on the topic:
Trump is a businessman. He understands things like depreciation and life-cycle costings. He's quite intelligent and hides it underneath his exterior bluster. In fact, its a vital part of his business strategy. He goes into a room with everybody underestimating him and says outrageous things hiding the fact that he has a very shrewd understanding of the real issues. Then, when the other side has committed themselves, he hits them with an unsuspectingly thorough understanding of the issues.
So lets make a guess at the real issues as Trump sees them.
1) The US Armed forces are too small and defense funding cuts have decreased their size and power to an unacceptable level
2) The US armed forces have an inventory of equipment that is aging and has been worked very had for the last decade and a half
3) As a result of poor business practices. US procurement is all screwed up and nobody will fix it because too many people have an interest (financial or otherwise) in ensuring it stays screwed up.
Probably a lot more but those three will do for a start.
Now, the great danger in dealing with problem one is that "increasing the force structure" is achieved by running on old equipment. This is an all-pervasive idea that always ends in tears. Old equipment costs a disproportionate amount of money to maintain and all it does is drain the budget of funds for new equipment.
FWIW, anyone who has crewed an old ship knows the effort required to meet our commitments means continuously driving the kids much too hard, actually wearing out the senior sailors and looses us a lot of the mid grade Officers and enlisted the fleet so desperately needs. It is like being forced to eat your seed corn.
So, the effect of solving this problem that way is to make Problem 2 very much worse.
Now, lets look at some present cost top-of-the-line numbers. (These are all FY17 and calculated on the same basis). All of these aircraft are in production.
F-18E/F is $77.3 million
F-15S is $100 million
F-16E is $43 million
F-35A is $76.8 million
F-35B is $105 million
F-35C is $89.1 million
There is no obvious financial gain by going to an F-18 for an Air Force procurement in its present form
but there is a production bonus. It would add a second production line for modern fighter aircraft and it would allow the replacement of some of the oldest aircraft in the fleet.
At this point, memories of the A-7 started to surface. Continuing the F-18 production line would also make additional F-18s available to the Navy as a way of helping fill up the holes in the carrier air wings. It may actually be a pretty smart way of getting more modern aircraft into the inventory, replacing the old aircraft and reducing inventory maintenance costs. It may not turn out to be practical but its an idea worth exploring.
As a side thought, its an interesting idea replacing the A-10 fleet with "A-18"s.
As for Problem 2 this is addressed by the above solution. Get the old, worn-out aircraft to the scrap-heap where they belong and replace them with new aircraft.
In that sense the apparent unit cost of the new aircraft can be partially recovered by getting rid of old, costly-to-maintain aircraft.
Behind this all is Problem 3 where Trump has definitely looked at the procurement system and cringed. The Air force One issue with Boeing was a shot across their bows. If it really caused distress and megrims at Boeing, excellent. It worked. Now we've seen a shot across Lockheed-Martin's bows with the hope of making them upset and confused. It wouldn't surprise me at all if we soon saw another salvo across OMB and DoDs bows soon.
@Desert Fox @Sarge