Of those, I'd go with the Yak-3, if the performance numbers are different to some degree than the Yak-9's we have now, when considering the game flight models. The numbers for the Yak-3 were better IRL, but that does not always translate well into game mechanics.
The Yak-3 was an air superiority fighter to the Yak-9 interceptors. As such, it would carry less fuel to be lighter at the expense of range, and was considered probably the best furballer of the war by many.
Now, as we often do not lift with full fuel in the arenas, thus lighter planes, I'd really want to know if there were other tangible differences between the Yak 9 and Yak 3 to justify the work being done to add it.
If there would not be much difference, in the game, then I'd rather see the limited development resources spent on a Lend Lease version of the P-39 and the Pe-2 to compliment the IL-2 added to the Russian plane set before the Yak.
A few specs from one online source. I left out those with relatively low production numbers.
Yak fighters_____name year speed sea-level speed at alt climb to5km turn sec climb turn ceiling range ready weight produced
- Yak-9T 1943 533kph 597kph @ 3930m 5.5min 18.0sec 1100m 10km 735km 3025kg 2748 made
- Yak-9U 1944 575kph 672kph @ 5000m 5.0min 19.5sec 1280m bad data 1070km 3200kg 3921made
- Yak-1 1941 472kph 570kph @ 4860m 5.7min 20sec 650m 9.3km 900km 2900kg ~3000made
- Yak-1 1942 483kph 559kph @ 4450m 7.3min 20sec 650m 10km 750km 2930kg ~3000made
- Yak-1 1942 500kph 571kph @ 3650m 6.0min 19sec 650m 10km 980km 2885kg ~2500made
- Yak-1B 1943 531kph 592kph @ 4100m 5.4min 19sec 1150m 10km 700km 2884kg 4461 (of 1942 and 1943 models)
- Yak-7B 1942 514kph 570kph @ 3650m 5.8min 19sec 1000m 9.9km 645km 3042kg 5120made
- Yak-9D 1943 535kph 591kph @ 3650m 6.1min 20sec 950m 9.1km 905km 3117kg 3058made
- Yak-9M 1944 518kph 573kph @ 3750m 6.1min 19sec 980m 9.5km 950km 3095kg 4239made
- Yak-3 1944 567kph 646kph @ 4100m 4.5min 17sec 1200m 10.4km 648km 2692kg 4004made
From this source, the Yak-3 falls between the 9U and 9T for speeds, around 2/3rd to 3/4 the range, but faster to altitude and in a turn, and a bit lighter (mostly due to smaller fuel load however). Comes down to the flight data HTC would chose to use in the game as to whether or not there would be much difference in game models.
