House Rules is House Rules and how you guys wanna play the game is up to you.
However, I personally would REALLY not like the rule because it tampers a little too much with the basics of the game. Sure, A & A is about stacking the odds in your favor where possible, but a lot of our most memorable games have hinged on a REALLY RISKY battle, that either succeeded or failed largely on luck. Dice rolls can be frustrating sometimes, but in a wierd way I think it actually ADDS to the tenuous realism of the game–throughout history, generals (including WWII generals) have tried to bring about circumstances in which a battle could be faught in their favor: but plans go awry; a single sentry could be asleep at his post, a single plane might make it through, a secret communique could somehow end up in enemy hands, a single platoon could hold out against overwhelming odds–in the chaos of battle, even small events can have a profound effect.
I think the element of chance is a vital part of the game.
On another level, I think your solution to the “chance” element needs to be tweaked a bit to be workable–rolling the dice and deciding whether to reroll or let stand on the basis of a hazy concept of “more or less likely” is gonna be bad news–it will lead to arguments. Also, how are you going to handle “research” rolls? These are NEVER “likely” to be successful–will you eliminate them, or impose a form of “progressive gains”–i.e. a particular power gets a particular technology on a particular designated turn? How about Strategic Bombing raids–how will they work? What constitutes a “reasonable” roll for a SUB’s 1st shot attack?
I’m not saying it CAN’T work–it’s YOUR house rule, you can play however you want–but make sure you know what you REALLY want out of the game before you tweak the rules: doing so can have a profound effect on the way games turn out…
Just some random thoughts…
Ozone27