It's easier than you think...
Attach a faucet to the shank (Tight)
Hand tighten the shank nut
Hold the shank nut with needle-nose
Turn the faucet to tighten
When it's good and tight, remove the faucet, straighten it up, and re-tighten.
This is also about the ONLY way to get a shank nut tight in a 3" tower with 3 faucets