I'd say Langford's natural position is actually half forward flank, rotating thru the mids.
Essendon tries to turn him into an inside mid two years ago and he was very slow with handballing in traffic.
The current setup of parish as the primary ball winner plus Merrett / Langford with McGrath a more defensive mid, seems to be working well. I think Perkins will take over McGraths role until Shiel maybe Smith / Snelling is back.
He definitely looks very comfortable in the current role. But you are paying ~97.5 ppg to get him.
That said, I'll be trying Poulter > Langford R14