In terms of a 1v1 fight, what does a pony do better than the d9 besides low speed turning?(and that only marginally)
Same with the 152?
Well, first of all, the 190 D9 isn't really a 375 mph fighter in typical combat configuration. Because of the D9's short legs, a drop tank is almost required, the centerline rack slows the top speed of the D9 down to 369 or so on the deck, 1 measely mph faster than a P-51D, a P-51 will retain energy slightly better than a D9 with a rack. Second, the Pony turns noticeably better, especially since it can pop flaps at much higher speeds than the 190. (True enough, the charts show the 190 D9 having a slightly better turn radius with full flaps than the Pony. This shows you how porked the Pony's turn w/flaps modeling is, but doesn't really help the D9, since full flaps come out at such slow speeds, the Dora is already DEAD before it can pop them.) The Pony also has much better forward visibility and guns that are arguably easier to hit with, although admittedly less deadly. Also, although both planes have radiators, the D9's seems to get popped much easier, almost any hit to the front quarter seems to do it, you can almost guarantee a glide home after dismantling a buff formation in a D9.
The D9's advantages over the Pony are acceleration and climb esp. below 10K or so, roll rate, and hitting power. This thrust advantage goes away at 13K or so though. From there on up, a D9 basically has little/no performance advantage against Ponies, and it just gets worse and worse the higher you get.
Primary thing the D9 has going over the Pony in MA conditions is that if you screw up and end up somewhat low and slow in the typical mixed furball crowd with lots of dedicate t'n'b fighters around, you can get your speed back quicker. But the Pony can egress, re-alt, and re-engage more times than the D9 because of its superior range and better climb on Mil.