It takes two weeks to get the momentum going. Great care is needed to avoid too many steps of armour being lost in the bocage. However after two weeks US Corps artillery will continue to grow to damaging proportions and ultimately shatter the defense outside Cherbourg. The German will ultimately let go of his tenacious defense as he sees more and more of his divisions being chewed up. By the end of June he should have formed his new line at the base of the peninsula in some depth.
Supply is an area of the battle that deserves special treatment.
For the Allies it's management will control the pace of the game. Only the Allied player can really afford to have units unsupplied and then only when his reserve of divisions has grown huge. Closely associated with supply expenditure is the use of artillery. The Defensive Fire Phase is really the main killing phase. As a general rule I keep the Corps artillery firing every turn, unless saving for a push.