Hmm, the key problem is the obvious chaos bits, then of course the armor style, one is plate armor the other is stylised gothic armor....
Edit: after some core investigation and eyeballing:
Should be possible, depending upon your bit arsenal aswell as greenstuff and scalpell skills even relatively easy.
The core issue will be the shields and armor plates with obvious chaos heraldry, however as far as i remember half the shields have skin and other mutations that would also fit the vampire counts...
Weapon wise, the hand weapons will be a bit of a obvious nope... Also chaos knights would look more bulky...
It's a question of how much your bitz box can overcome the issue at hand i'd say.
The lances should fit if you get rid off the chaos arrows on some of them.
And the armor is the same. Fill in like the video with some greenstuff and you should be golden.
Do you have other Vampire count bits?
Also i believe there are some greenskin sabres not to disimilar.