Blood Knights... without Knights?

Hello, everyone. I have a crazy idea and I wanted to know what would be in store for me before committing a lot of money to it. How integrated are the Blood Knights to their steeds? If I leave them off, will I have to do a lot of gap filling or sculpting lost details? A friend of mine gave me the horriblely fantastic idea to use the upcoming Vampire Lord on Nightmare and the Blood Knights to try and create a nightmarish My Little Pony unit based on the main characters. Yes, it is as cursed as you'd think, but it's just crazy enough that it'd work.

Tl;dr If I leave the Blood Knights off their horsies, how much extra work will I have to do to repair any holes/gaps in the plastic

Thank you in advance, I look forward to recieving this wisdom.