That's a fair point actually about mentality/intelligence because Schweini uses all of his ability with his bravery on AND off the ball. The thing about 'if only an added bit' of calmness under pressure is actually a big deal for me. Peak Carrick might had been fine being under pressure/when pressed/having someone on his back but that was a 2-3 year period at best. His whole playing style and career with us imo shows he is not a great player under pressure and subsequently plays like that i.e he removes himself as an option in those really tight situations.
Schweini (and your Herreras, Fellanis, Valencias, Matas) consistently offer themselves in unfavourable situatons and are able to do something good with it (recycle possession forwards, turn on the ball, play a forward ball etc). Carrick simply does not or certainly not enough of it.
Schweini is easily another level better imo.