As to stacking warcards all in a single position, you could still
technically flank them by surrounding them on three sides. Their units could
then not concentrate all their fire in one position, thus reducing their
effectivness, which is the whole point of flanking anyway. Everyone one
complains about not getting a numerical bonus for making flank and rear
attacks, but many times the advantage of flanking is the fact that more
units can strike a unit at one time, splitting the units defenses and
causing more chances to hit. Stacking rules negate this advantage, so I try
to disallow stacking in my wars (no more than one of a side's units in a
position). I believe the best way to look at it is the way that the
Birthright computer game handles it, where there is no stacking and any
additional units are held in reserve until a space is open on the back line
of their forces. Of course I allow exceptions, such as during the move
phase, you may move a unit to a space already occupied if the unit already
there moves out of it by the end of the move phase. This can make for some
spectacular moves, such as just as your infantry begins to withdraw, a full
unit of calvary comes charging through them and directly at your opponents
line. But this is all IMHO, and there are many ways to look at it. The best
idea, take the warcards as they were meant to be: a quick but good system
for running wars. If you want more detail, use something else.

"Are the bones of your sins sharp enough to cut through your own lies?"

P.S. In case you are wondering, all my quotes are from "The Crow" by J.
O'barr. Great book, check it out. Could be used for a good Halloween