lol that's exactly how I play. Normally have 3 fleets of 6 BB's and they wreck everything.
Except I do min-max research and boost stuff, as the slow down doesn't apply to the research I want, as the way I boost it makes up for the few months lost boosting others.
Priority to start is hull, control something n rangefingers. Bigger ship with accuracy, that's normally all ready for my first shipyard upgrade finishing, and the next generation of 6 BB's to be built. Next two years, is engine, funnels, guns, control n rangefinders.
As soon as numbers appear on the research boost them. If no numbers are present boost the 3 next things you want.
Within 6 years you've won, within 8 1/2 those 6BB's will have a 20k tonnage advantage and 16-18 12.9 fully extended barrels, with however many 6 or 8 inch secondaries fit. Times that by 6 BB's being in the battle, and the shells lobbed during a full 6 ship boardship, is a site to see