Seven Demilancers is pretty scary. Against five Knights, they might not be trading too equally though. Even in advantageous numbers, seven against five, that's not going to be a fight that they win nowhere near due to that severe stat difference.

JD early aggression can really hurt against House of Lancaster because JD gets experience even for taking down buildings. If there are houses in front of your base that cost 300 resources each, 30 experience for every single one of them.

King's College is an excellent landmark when you're up against these knight civilizations like JD, like French because of the Call of Essence upgrade where your knights get +6 damage, like heavy maces for knights.

Demilancers don't have great stats damage-wise, but when they die, they give the full amount of experience of a knight over to JD. So if any demilancer goes down, that's an additional 24 experience for JD right there.