I don’t think this acquisition has anything to do with Cook. I see it as serving multiple purposes.
1. Swapped for a seldom used & bad fit - Moss.
2. Special teams PR / KR
3. Insurance if DS should become injured.
4. Allows Dorsey to give DS a blow occasionally or use these backs in any combo for a new offensive wrinkle.
Beane & McD love high character hard nosed guys.