Quite a few countries do have committees that operate at a more technical level. You have a committee under consumer price index, and another one on surveys or national accounts.
I do know that these exist in Canada as well, but their functions are typically somewhat different from the overall advisory functions that these statistical councils have. Indeed, you are right that the comparability may be limited. When we talk about the council in France, that includes, at least partially, some of these technical functions that you've been alluding to. For example, with Switzerland, I am part of the Swiss Federal Council. It has 10 members, and it works exclusively at this more strategic level.