Bob lowest point of gravity & tension on line transfer of shift in equilibrium.
Huh?
As best as I can make out,
Charles is claiming that if the bob is not absolutely symmetrical about its long axis (as in an irregular lump of rock for example) then there's some sort of overturning moment (?) introduced into the suspension system. Obviously though, any shape of bob works as a pendulum, as its individual and unique centre of gravity never varies, and the suspension system is absolutely flexible.
IF Charles's perfectly spherically-shaped bob was fixed
rigidly to its means of suspension, but
not along the vertical axis of its centre of gravity, and that means was a
rigid rod, then one can then imagine there
would be a few strange forces induced into the mechanically closed system.
I can't be bothered doing the maths, but
Charles might care to clarify if this is at least similar to what he's getting at.