Hi Pierre,
Hopefully I am not misunderstanding your question; aside from an "all of the above" answer for influencers in content production, I'd say it does depend a bit on how developers are being paid -- by the word or by hours spent (or by some other factor).
Having previously worked on software content, a huge amount of time in content development was involved in validation, from product experts or in-house engineers, for example. Research was a secondary concern, and word count was a factor, but only in terms of the final output, as many of our content developers were paid by final word count.
That said, when content got stuck in long, involved validation cycles, it can cause a lot of churn for the content developers to parse -- it can be extremely expensive if you're not careful. The solution to this problem that we used was a dedicated resource (or at least a point person) who makes sense of the feedback, distills it into actionable items, and sends it to the content developer. This person would also be a point person for translation-related questions (clarifications on terms or meaning). This did allow us to cut a significant amount of time out of our content development cycles when working on major site-wide projects.
I hope this helps.
Maria Varmazis