Yes, we need more Soviet planes (for special events, anyway), but . . .
the ones we need are the Yak-1, LaGG-3, and Pe-2.
The Yak-3 got into the war after the Yak-9, and it has very similar performance to the Yak-9. So, it doesn't add much, in my opinion. Late-war Soviet is already well covered by the Yak-9, La-5, and La-7.