Sitting still usually gives the defender a huge advantage.
He knows the enemy is coming, and doesn’t need to move his supplies very far once they get to the battlezone.
Traditionally commanders want to attack with 3:1 odds, for a decent chance at victory….probably because a defending soldier is twice as effective as one attacking.
Just saw something on TV about Pickett’s charge, and the South only had a 2:1 manpower advantage.
A VERY risky attack by anyone’s standards.
Even in A&A the axiom holds true.
Making a 3:1 attack should succeed, a 2:1 attack is daring, and a 1:1 attack is suicide.