Why keeping armoured divisions in Europe was not enough

Would retaining one or two heavy armoured divisions in Europe have changed NATO's position?

Only if the alliance also solved rail movement, sustainment, command, and the circumstances in which the divisions would be used.

The answer does not treat the continued presence of one or two armoured divisions as a complete solution to European defence. Railways might move them as far as Poland, but the force still needs a destination, sustainment plan, and operational purpose beyond that point. A joint corps with American, British, and German divisions sounds formidable on paper, yet it immediately raises questions about command, readiness, and when the formation would actually be used. Those institutional choices determine whether the equipment can respond quickly in a crisis. Force structure is therefore a system of transport and command as well as a count of tanks.