After playing several games, I think I may have developed a cohesive allied strategy which can be very effective. The strategy is fairly straightforward, but requires very specific first turn actions.
The main objective of this strategy is to make a unified American and British thrust towards St. Lo at the very beginning of the game, quickly creating a stalwart line either in St. Lo or adjacent to it. St. Lo may seem very distant near the end of the game when Axis units crowd the game board, but in fact it can easily be occupied by turn 4.
The shore bombardments main priorities are the two boxes in Omaha beach. It is very important to kill the 4 german infantry and 3 anti-aircraft in that territory quickly, as they are only large force seperating you from St. Lo. If you have leftover shore bombardments go after the adjacent british beach, if you do not get them with shore bombardments use the bombers to take them out.
This heavy concentration leaves you relative vulnerable on the Cherbourg and Caen fronts, so instead of strafing Axis reinforcements use the fighters to pin down the german tanks near Cherbourgh and dissallow the Germans from harming your British landing forces weakened by the untouched Eastern pillboxes. This can be done with as few as 4 allied fighters, so you can still get shots on Renn reinforcements if you wish.
How this will play out is your British landing force at Gold Beach will quickly dominate the two infantry, and your landing Allied units will struggle but start to chip away at the german units. By turn 3 British reinforcements and Allied units will have most likely destroyed them. However, if you have poor fortune and have not, your game is not bad off. While your 8 or so units are caught in combat at Omaha beach, British units will be landing adjacent and IMMEDIATELY advancing on St. Lo. Needless to say, as many British reinforcements as possible will be placed at Gold beach on the first and possibly second turn. After that the majority of your British reinforcements will be required in the East.
By turn 4 you will have British units entering St. Lo, and a freed up allied beach two movements away from St. Lo, and only one turn for tanks. If the Germans attack, you will be able to reinforce St. Lo and can utilize fighter cover.
While doing this, be on the defensive near Cherbourg as you may be outmatched, and take Caen relatively quickly (turn 2 or 3 or 4 possibly). While your forces may be weakened and hurting for reinforcements, utilizing most of your fighters can isolate Caen from German reinforcements and allow you to draw a defensive line which includes Caen.
By turn 5 you will have control of St. Lo or be battling for it, and most likely waiting on Cherbourg. Bombers can be very valuable assistance for hurrying the Cherbourgh assault, and it allows you to avoid “overcompensating” for Cherbourgh and stranding units. Try to get Cherbourgh by turn 7, because then you will have 3 full-turn opportunities to win the game(8, 9, and 10). Regaining the cities at this point is very costly for the Axies with good fighter use.
What makes this strategy very effective is that it places you on the defensive end in both St. Lo and Cean, rather than trying to assault them. The defender has a definite advantage as infantry hit more often and the defender gets the first counter-attack against a weakened force. With your fighters, defense becomes even more effective. In addition, if you get the early city control you have a definite tactical advantage.
Of course the Axis can counter this by placing more reinforcements in Rouen/Chartres, but Axis players rarely place those first 5 precious tanks farther away from combat. Placing fighters in Renn/Chartres discourages that also. In addition, it is difficult for the Axis to get enough units to flank the Allies, so a potential early defense in St. Lo will most likely only take place in the city, creating perilous fighter conditions (You can simply place your reinforcements safely to the rear of St. Lo).
It is quite likely that the Germans will have lost relatively few units, so keeping control of the cities will become a game of pinning down and delaying German units rather thank trying to kill them. You will not have unit superiority (which is always dependant on rolls however, and not a good solid strategy, especially considering the German makeup of units is superior), but with your fighters and the fact that you can attack first in a turn to initiate battles and pin down German units will give you a decisive edge in the event of a large unit buildup.
This strategy is not fullproof, but I believe it relies less on good rolls and gives the Allies a very good chance of winning the game. The strategy is highly aggressive in early movement, but with the purpose of putting the Allies in a defensive position early in the two most contested cities. Another strength of this strategy is it takes full advantage of the poor Axis starting position, and attempts to gain superiority BEFORE Axis reinforcements brighten the Axis situation.
Thanks for reading, if any part of this post seems especially incoherent or needs to be elaborated, please point it out :p