I actually do agree with almost everything you say. Personally the training of the tank crews whilst difficult is probably easier to do than the training of the engineers who will maintain them as special tools would be needed, spares from vision blocks, to tracks, to the complex engines and all the new electronics learnt and understood.
However the West only have a finite number of ex Russian T72ish tanks available. If there are to be supplemented then the Leopard is a good tank as they were used by many countries and there will be considerable stocks around. There will be differences between the German, Canadian, Dutch, Italian, Belgian and no doubt others, but the core tank will also have similarities
Challenger 1 tanks for example would be useless as there were so few of them made in the first place.