much was there unwillingness to use them; the ‘Panzer’ flagship tank for example, was known to be ‘invisible’, not because it was stealthy, but because no one on the ally side ever actually saw one

It didn’t help that they were so complicated that their crews weren’t able to work on them at all. Panzers would have been a decent tank if they weren’t constantly needing to be hauled back behind the lines to be taken apart every 50km.