I could even eliminate words with letter 'e' even if they shared the common position because they didn't share all positions.
Ah, that is what I have left to implement. The method I initially used is the exact same as the one you use besides the 'all positions' part, which is why yours works better.
I don't mind occasionally having to reinvent a wheel; I don't even mind using someone's reinvented wheel occasionally. But it helps a lot if it is symmetric, contains no fewer than ten sides, and has the axle centered. I do tire of trapezoidal wheels with offset axles. --Joseph Newcomer