Monahan and Danault kind of seem to address different "needs" so to speak...in a perfect world you'd run Zibanejad, Monahan, Danault down the middle and you'd be strong as heck (but impossible to afford).
Danault seems to be the responsible two way center we all kinda want but might not put up enough points to satisfy us and isn't a goal scorer. Monahan will put up the goals and it sounds like do more net front dirty work but isn't the two way all situations guy we dream of.
Which one is best for the team taking into consideration cost to acquire and contract status/demands? Tough questions.