The only info I could find was that the Yak 3, an apparently very good dog fighter, did not have very good range compared to the P-51 and lower ceiling. Its light weight would question its armor protection. An interesting series on youtube titled The Attackers, which is based on front line aerodrome flying Yak 3s has the pilots complaining that the Bf 109s had armor seats, implying that the Yaks did not. I enjoyed the series which is a mishmash of combat and romance but shows what a combat squadron of Russian Yak 3s was like, at least from a Russian point of view. I would rate the Yak 3 as a very good low level, short range, tactical escort but not a strategic escort.