100% wrong. This is exactly the sort of thing that the factory manual is for, and these forums would benefit a lot from people knowing the information and procedures outlined in the FSM.
And it would not eliminate the need for these forums. The FSM is very beneficial for basic adjustments and stock cars, but since many of us do not drive perfectly stock cars the forum is a great place to bring up more advanced questions and deal with the differences from the FSM that need to happen when modifications are made.
On this very topic the FSM is very helpful with setting the ride height, the procedure that should be used etc. But if you run radial tires and your ride height isn’t set to factory settings, the alignment specs in the FSM are totally wrong. But the knowing FSM’s procedures is very helpful as a base to start from before you make changes.