> Impact weapons were rare when hvy armors were in use No they weren't. Cheap and cheerful mauls and war hammers were very popular on mediaeval battlefields -

> Impact weapons were rare when hvy armors were in use No they weren't. Cheap and cheerful mauls and war hammers were very popular on mediaeval battlefields - the archers at Agincourt used them as secondary weapons against knights for instance. And of course it is easy to turn a two-handed sword into an impact weapon as well - turn it around and use a pommel strike.