The Gov't changed AFTER the decision to build M60.
But its a no brain decision Congress had already decided not to fund M48 production after 59 the T95 programme is 4 prototypes. Its going nowhere and Congress knows it and part of that program was the armour which is also going nowhere. So whoever is in the presidency its new tank now. So they do the sensible thing, and put the 105l7 which works, and its T95 turret on an M48 hull with a proven power plant and call it new.
Then they proceed to fuck it up with the A2 and fuck up the MBT70 program then get the M1 which actually combines mature technologies. And having learned their lesson the Children of the design team go into naval architecture and develop the Littoral Combat Shit.
This is not a bug btw its a feature of US procurement over decades everyone has issues with this for obvious reasons ( there are new technologies, requirements do change and evolve, politicians have constituents money is not infinite but its cheaper to spend on R&D than actually making things) but the US started coasting in the mid 50s and its not until the Rumsfeld era DoD ( Reagan presidency) that the shit got cut out.
You overestimate the number of T-54s in service.
No NATO overestimated see also Bomber Gap, Missile Gap, Commie Hordes, etc etc etc. But the decisions are made against the background of these estimates so its a real consideration.
F**k your independence, buy and do what the Germans do
Kinda. But then you have subordinated most of your armed forces to NATO anyway.
Practically the Germans are building several thousand tanks anyway the unit cost will be low - ditto US tanks, French APC etc etc. You will get more bang for the buck buying Leopard unit number 2001 than a locally built and designed Tank Destroyer unit 1. What you do is deal with KraussMaffei to get work on components, if not this time then on the next model and buy in on the design and development of the next model from the start and tweak it in ways you want for your service.
If we exclude the US and France for most of this period there has been a very high degree of European cooperation on procurement and manufacture of kit. The French actually tend to be good partners up to a certain point then amicably walk away.