Set bowl first. Set on wax ring, but do not tighten bolts.
Set ninety that connects to bowl loosely.
Install tank by guiding tank against wall slowly lining up ell with connection on tank.
Rough gauge the connection and slowly get both nuts snug.
While still holding tank, have someone send lag screws with fender washers with rubber washers against the porcelain into the wall with connecting to solid wood.
Should be able to make fine adjustments on ninety and bowl with no problem; just do not jam that ninety that connects to bowl and tank in a downward position.
It will leak.