Bruno wants to play with inside forwards if we play a front three. Adama can't do this on the right, he becomes a crossing and running towards the corner flag machine. He looks better at it on the left, but his goals record isn't an accident, and there's precious little by way of link up play, it's just he looks more dangerous running into a central area rather than away from goal on the other side.
Trincao is more equipped for that kind of role. He's also a better footballer than Adama, but with miles less explosivity and at present fairly limited impact on games. Whether it translates into any actual end product, we'll see.
I'd rather use whatever we get from Barca on a central midfielder who can adequately replace Neves/Moutinho in a two when need be but also has the ability to run beyond the forwards in a three, like Ramsey did for Villa last night. But it's not my choice.