Knockdown this is excellent for breaking guards and defense based creatures.
There's Surging Wave and Tanglevine already to handle Guard-Interceptor type creatures.
Swap 1 Dispel for Nullify
Could you elaborate on this one ?
I see far more upside in a Dispel than a Nullify for this book.
Grimson for the Crossbowman your battle order is Piercing +2 need one more sbp for Grimson though.
The main role of the Crossbowman is to finish creatures with a few hitpoints left or to soften up targets for the Warlord.
He can also plink a Wizard and trigger his Voltaric Shield for example ...
The fact that he has Piercing+2 makes him ideal for his role as he can do an average 3 dmg most of the time.
At 11 mana he's affordable.
Grimson is less suited for this role imo because he's more expensive, he doesn't have Piercing and my QC is far too valuable to waste on a Battle Order.
Another minus for Grimson is that he wears a Bull's Eye.
If he shows his face, he's going to get focused on and he's not that hard to take down really.
The Crossbowman is a creature that is seen less as a threat and has more survival chances in my experience.