If language is no longer part of thought, then sure, breaking down... thought... into many different mechanisms also makes sense (quite a bit of sense actually).
From there, you ask: "What is the fundamental aspect underlying each of these different faculties?"
The authors say their opponents want a singular fundamental aspect, supposedly because of parsimony or Occam's razor (but this is the authors' framing). It's not clear to me who's account is more likely.
From there, you ask: "What is the fundamental aspect underlying each of these different faculties?"