I don't think people appreciate how much money the A's have to spend this winter. In the past decade, the A's have pretty consistently increased payroll every year, with only a drops after the 2007 and 2011 seasons. Before non-tender decisions, the A's have around $64 million in commitments, to a payroll that was $83 million last year. Assuming a raise in available payroll to $90 million, that's $26 million to play with. That's a huge opportunity.
That said, this is a decidedly conservative offseason plan, based off the idea that the 2015 A's were deceptively close to contending.