I suspect the problem is mentoring. It took me months to get basic Haskell.
The people I mentored, though, could clarify any misunderstanding and get explanations from multiple viewpoints from me -- after years of experience with these abstractions. With such mentoring, you don't have to go through all the confusion phases.
The core point here is that Haskell is a more complex language that requires understanding and applying more concepts to write effective idiomatic code. Mentoring does help, but you still need to build a mental model of using the language, and there isn't a shortcut for that. Clojure requires a smaller mental model than Haskell, and that makes it easier to learn. The end result is that you have to spend less time ramping people up.
If Haskell works for your team that's great though, it did not work for mine.
The people I mentored, though, could clarify any misunderstanding and get explanations from multiple viewpoints from me -- after years of experience with these abstractions. With such mentoring, you don't have to go through all the confusion phases.