A TUG with Keil characteristic is partially immune to flank charges.
If charged in the flank, if in a block with another pike with keil, it will fight as if the bases were facing the cgarger and one rank deep.
Now what about if the keil is already engaged to the front and fighting to the front or charged to the front ?
How do we resolve it ?
The flank charge is a flank charge as the phalanx is already fighting to the front or
The phalanx may fight "as if" one or two bases are turned on the side protecting the flank but then what about the frontal charge/fight

?
Some might argue that it fights to the front and has no flank no matter what but that would really be strange to me !