you got me to thinkin'
Hypothetically, If they give him the title of "safety" but bring him in with as a strong safety lined up at the second level (essentially, 4-3, cover-2), is he still a safety? in title, yes, but functionally no; he's a WLB on that play. For a players function, it depends on where they line up when the ball is snapped on any particular play.
Similarly, if a player has the title of TE but he is in the slot position (Flex) when the ball is snapped, he is not a TE on that play. To be a TE, you have to be "tight" on the line. If one is not tight (alongside OL) then they are split and functionally different on that play.