What's his name (Mark Hanna?) has flown the P-51D and the 109G and says the latter is more maneuverable. P-51D pilots in WW2 ETO were well trained and up against n00b opposition for the most part.
Without knowing the speeds, altitudes, configurations, weights, maneuvers, power settings, etc, of such mock dogfighting, it is difficult to say how useful such information is. One would think for safety's sake with old and rare warbirds, they wouldn't be running wide-open or doing high-G maneuvers at speeds beyond Vma.
Which is not to say I think the P-51D can make a smaller mininum turning radius than the 109 G6, physics tell me it probably can't, unless there is some factor we are overlooking. A moderate differance here doesn't nessecarily decide dogfights though. I wasn't comparing the P-51 to 109s anyway, I was comparing them to Jugs, a plane with higher wing-loading and worse power-loading than the Mustang, that was acknowledged to be turn less tightly than the Pony. A Pony that turns somewhat better than the Jugs do in AHII right now, would be very, very deadly IMHO.