A good relationship between them can only develop over time. Before that, they really have to take each other on trust, going off whatever has been agreed between them, and the specifications of their roles.
It's a difficult balance to get right, technically in the hierarchy Brands surely has to outrank Silva, but we don't know how that will turn out in practice.
As I see it, Brands has to deliver a structure to support the manager and team off the pitch, and Silva has to work within that structure and deliver on the pitch.
A "partnership" is fine but someone has to be accountable if and when things go wrong. Yes, there can be shared accountability but Silva will find his neck on the line far quicker than Brands so realistically whilst Silva is the fall guy, Brands is, or should be in overall charge of all football matters, and accountable to the board for success or failure.
Either way, we need them both to succeed, and stay long-term.