the difference with the power rangers was it was all the same thing.
They fight those "putties" then see the main baddy. Fight him normal and start winning. Baddie gets "enlarged" by head evil person. Rangers start losing. They call upon those mechanical things, form together, and win, then they laugh at those 2 idiot bullies at the end.
The medieval knights fought real battles, where the outcome is uncertain till the end, and there is no "morphing"!!!