[Bruno]

Another critically important thing to remember is that combat doesn't occur in an infinite flat plain with no walls or obstacles. I mean, unless you really want it to, but generally roleplaying games (like real life) have more interesting settings.

Having more mobility means even more when you have terrain features to work with, as you can often maneuver your opponent into an area beneficial for you.

Many people at 1/3 HP or less are going to be picking options like Retreat to make up for substantially reduced defenses - when you have better mobility, you can push them back where you want them to be and always have the option to withdraw, or you can kite them around obstacles, or attack and then step back, leaving them two hexes away after their retreat.

Superior mobility means you can circle around behind them and attack from behind, stacking further defense penalties or even avoiding them entirely (see Runaround Attack for details). Even just circling to their side to make use of the -2 to defense for a flank attack is useful - with dodge halved any additional penalty becomes a major impact.