Players will always take some time to adapt. An amazing first few games doesn't necessarily mean anything (MatteoD, MemphisD, AlexanderButtner, FedericoM), nor does a horrible/ordinary first few games/weeks (NemanjaV, RoyK, PatriceE, Fred). It's how they behave after that and their ability to blend in with the squad. Some get ahead of themselves, some think they can start commanding the dressing room, some start chao keng.
So let's not knee jerk and start thinking/determining whether BrunoF will or will not lift our squad. We used up our luck with Henrik Larsson long time back (in terms of instant hits whom was actually consistent), and maybe we're due for another one again, but who knows. BrunoF must have some level of self-confidence and determination to want to come to EPL to prove himself - we can only hope he has the same/close enough level of desire as CristianoR.
Someone mentioned Nani a few posts back. Suffice to say I think most would be happy to see him in a United shirt again than some of the often mentioned names.