I say it's riskier to hire an inept North American coach than it is to get Jalonen for example. Teams just don't have the balls to do it.
It really isn't.... look at the retreads in last year's cycle:
Monty - best regular season in history (disappointing playoffs obviously)
Cassidy - Pacific division champs, in a fight for a move to the conference finals
Maurice - playoffs, and in the midst of their best playoff run since 95-96
DeBoer - turned a non-playoff team into one that has a legit chance at a Cup
Torts - TBD... thought I'd say Philly outperformed expectations this year
Bowness - got them to the playoffs, but are the issues his or leftovers from Maurice? TBD
Quinn - IMO clear failure, but I think he sucks as a coach
So ~4/7 success... maybe arguably 5/7. Over 50% success rate though.
Now the new names:
Lalonde - TBD, but Detroit has looked to take strides
Woodcroft - Success IMO
Richardson - Failure IMO
MSL - TBD leaning to failure as a coach, individuals took some strides
Lambert - what's new is old? Worse than Trotz IMO, but team was in the murky middle.
1/5 is a success... that might get to 2/5 or 3/5 in time, but a big IF. The previous cycle is much the same story.
Teams go with re-treads because they work. Gallant will almost always give you a great first season (somewhere in years 2-4 it will fall apart). Maurice is great at getting his team to a playoff level and holding that. Ruff has a system that will almost always get a team to a high level of play (not typically enough to get a Cup though). DeBoer will get the most out of a team and his system is difficult to play against, he works his players to death though. Sullivan was a retread that got the absolute most out of the late prime Penguins.
Saying that, new blood typically has a longer lifespan if they make it past the first 2 seasons.