Yeah, I think whilst Fernandinho does an extremely important job that really ties our attack and defence together, he's arguably the most easily replaceable guy in our team. Part of the reason for his significance I feel comes from the lack of immediate depth we have in the position, but as you say when we've rotated it around a bit in the middle we haven't suffered too much.
I love the guy, and I'm happy for him to be in the team for as long as his legs work; he is a really great player for us. But skillset wise, he's not the MOST unique right?