Thanks for the review, Panos. It's not my theme but I like to keep up with what's happening elsewhere in the world of Playmobil.
Like you, I ask the question, "Why did Playmobil introduce them?" Maybe, testing the idea of fantasy themes? Who knows?
The sets do show how Playmobil have moved away from authentic detail in their knights. The long shield first appeared with the crossbowman and with him it is right but I'm not too sure about an archer with the more traditional bow having a shield like this, but I may be wrong. Similarly, with the original catapult set it was men-at-arms with it, not armoured knights.