Use of Feigned Flight by Breton and Norman armies

[Wizard of Oz]

I recently did my own little solo refight of Hastings. In it Feigned Flight did not have the desired effect, however, with the changes to the Breton and Norman lists I am now not sure how that can really work, with no Flexibles to really put it into effect. I'm open to any advice.
For those interested, William did not succeed in my refight, but it was a very close run thing.
Regards