I'm going to wait and see how this all plays out before I judge it or get worked up. At the end of the day, Coyle plays a small game. Like really small. People here reading his height and weight and extrapolating out that he'll be a physical player are going to be sadly mistaken. He's more Jimmy Hayes than Ryan Reaves. He's got a big body but doesn't use it very effectively.
As for Donato, he didn't seem to fit here. The team wanted him to be something he's not, which I think is part of the problem organizationally. They take natural centers, don't like their games for that spot so they shift them to wing, and rather than let them play to their offensive strengths, they go to the extreme where they expect the player to become a 200 foot complete guy before they're comfortable with said player being on the ice. I think if the right organization gets a guy like Donato and let's him play to his strengths, he'll be a very good second line scoring/second PP unit type of option.
It just feels like at the moment they sold low on Donato and not because of the player, but because they're stuck organizationally looking to discover the next Patrice Bergeron.