MLS is such a unique / unnecessarily complex league structurally that I would say it is near-impossible for a "name" manager from Europe, (or anywhere outside of MLS for that matter) to have an immediate impact on an MLS squad. I thought that CFG hiring Jason Kreis was an excellent move on their end. He had developed a system of playing at his previous club, was working on a limited budget, and knew the league from his time at Real Salt Lake. Real Salt Lake were never an easy team to beat for years, and won the league once. MLS is such a complicated environment you have to have people who inherently know the system. I think he could have gotten more time, but I don't know all the facts.
Being from Seattle, I got to experience watching an expansion club with big money start out in the correct manner. Seattle poached a long-time MLS coach in Sigi Schmid who had won several titles in MLS with different clubs, and is currently the most winning coach in MLS history. Our General Manager publicly acknowledged deferring to Sigi Schmid's experience when it came to identifying transfers because of his vast experience with the league. Sigi knew which players to bring on from the expansion draft (as should Jason Kreis have known as well). The differences I see between Sigi and Jason is that Sigi had experience dealing with bigger name stars, whereas Kreis may not as much at Real Salt Lake, and that Sigi may have had more control selecting his team from the start. Furthermore, Jason Kreis worked with a very good GM at Real Salt Lake, and together they did amazing things on a very small budget (Interestingly, last year Seattle's part owner/GM stepped aside as GM in order to hire the GM from Real Salt Lake who worked with Jason Kreis). I know Claudio Reyna has some MLS experience, but in order to succeed in the league you have to have a whole team pushing in the same direction. There is so much parity in the league, if you don't operate as well run machine, you are simply going to be poor, or ordinary. Teams can win MLS having no, or very few, stars on their team because they have a system, and they implement it well.