Obviously more experienced troops will perform better than green troops, but it depends what you really mean as green. True a lot of Allied troops that landed in Normandy were relatively green, but the Allies had been preparing for Overlord for a long time and the troops had large amounts of training. This is massively different to a soldier who has just had a rifle shoved into their hands and told to fight.

I'm not going to say that combat experience made no difference to battle outcomes, but i will say that it is often overstated. In reality soldiers in the war gathered experience relatively quickly, but soon reached a level of diminishing returns after that. For example, a unit with 6 months combat experience performed much better than one with no experience at all, but would not perform much worse than one with say 2 years of experience. Therefore soldiers were able to reach a level of parity with the opposition relatively quickly. So while having experienced troops is a bonus, i would argue that it's less of a factor that manpower, weaponry, technology, tactics and strategy etc.

The main advantage of experienced troops is a certain coolness under fire which makes them less likely to panic. This works better when the veteran soldiers are mixed into formations made of relatively green troops because having people who know what theyre doing improves the morale and fighting ability of less experienced soldiers dramatically. Germany divisions towards the end of the war were often a mix of veteran soldiers and new conscripts. While a veteran unit fighting together is formidible, the logic went that mixing veterans in with new recruits made a much larger force fight more effectively and was therefore worth it