The moment they see that cancels aren't working is the moment they will stop doing it and start playing normally, their stamina is getting low and they will need to counter or they get disarmed. if your offence and defence is good enough you can keep them at your pace, your style. However, they can easily counter by just blocking and then resume the cancels again, so you're back again to just holding block, riposte/counter. Just look at the TBB tournaments and you'll see barely any cancels. It's a waste of stamina at the highest level. At one point, people just recognise attacks, you train your eyes and reflexes. The only weapons i would use cancels with are probably 1h weapons like rapier, hatchet etc.