Elliot is an abysmal midfielder, he's missing most of what you'd want from a midfielder in our system and hasn't improved at all since we first tried him there at the start of last season. He's a luxury player that needs to be carried by the rest of the midfield, playing in a midfield too old to carry him, and he doesn't even provide the goals/assists to justify sacrificing the control you'd get from a more rounded player.
Carvalho isn't a midfielder at all, he played there when we had dire injury problems and struggled, and we've made no attempt to use him there since.
If I had to choose between signing two midfielders and limiting the minutes of two youngsters, or playing them at all costs and accepting years of poor form in the hope they'll develop into mediocre midfielders, yes I'd absolutely sign new players.