The 109G-6 neither outclimbs nor out-turns a P-51B at 30k.
Sorry -- I meant the D and should have been more clear and said "the G-6 outclimbs and outturns the P-51D at 30k." I think that the G-6 might outturn both the P-51B and D at 30k, but I would have to test it to know for sure and thus could be wrong in my current suspicion.
At 30k the 109G-6 can't quite manage 1,400 fpm, while the P-51B can just exceed 2,000 fpm. At that altitude, the 109G-6 simply lacks the power to sustain maneuvering without losing big chunks of altitude. The 109G-6 faces the same issues against the P-47D-25 at 30k. The Jug is still making sea level HP at 30k. It can dump flaps to maneuver, where doing so in the 109G-6 means an unwanted stall if any attempt is made to match the Jug.
If I were to pick a fighter for high altitude bomber escort, I'd pick the P-51B. The Spitfire Mk.XIV has similar speed at 30k, but lack the legs to go more than a couple of sectors.
P-51's and P-47's (and especially Spit 14's, but they are rare in scenarios) are great planes at 30k -- I'm not saying otherwise. I do agree that P-51's and P-47's are better than 109's in some ways. It's just that I feel that 109's are better in turning and sometimes, depending on which particular matchup and which alt, at climbing. In scenarios, the 109's, including the G-6 and G-2, do OK vs. P-51B's, P-51D's, P-47's, and P-38's at all altitudes up to 34k. Neither dominates the other overall in scenarios, and they are well matched in that environment. What ends up being much more important is numbers and group tactics.
One would think (I did think it too, until I flew the 109 many times in high-alt scenarios) that the P-51's and P-47's would have such significant advantages at 30k or 34k that the G-2 and G-6 would be annihilated. But I found that not to be so in the scenario environment. One big aspect is that everything has constraints at 30-34k. Up there, one hard turn blows such huge amounts of energy that even a slower G-6 to blow through P-51 and P-47 sweeps more often than not (talking from much personal experience here flying them in scenarios at 34k against a wide assortment of pilots, some of them very good pilots who are the opposite of inept). Also, it's hard to kill anything at 30-34k if the opponent is willing to pull a decent number of g's to get out of your way, no matter whether you are the P-51 trying for the 109 or vice versa. Most dogfights starting at 30-34k don't get resolved until a much lower altitude (unless it is against an escort who isn't evading as hard as possible because he is trying to stay with the bombers). Many-on-many fighting changes the dynamics of the fights as well.
The toughest plane I ever fought at high alts in scenarios has been the Spit 14. That one, I do think is better than any 109 model in every way at high alt. Still, even there, high alt and many on many are the great equilizers, and the groups I was in did OK against them in 109K's (The Final Battle) and 190D's (Winter Sky).
