Too risky to have both D Cook and Fournette?

Is it too risky to try and roster both Cook and Fournette for playoff push?
Thinking of trying to offer Fournette owner a trade in plans to have an all star team come playoffs.
Current team:
QB: Mahomes
WR: Nuk
Flex: Theilen
Te: Kittle
RB: Lindsay
RB: Coleman
D Cook
C Thompson
A Jones
R Wilson