Not quite so, the Yak-9U is IMO more durable than a P51-Delta. I've taken stray rounds from a La-7 and I've been banged up but i have remained afloat. Also an La-7 isn't hard to shake off of your six if you notice him early and have some E to work with, it's not that maneuverable since majority of the La-7 pilot's keep the throttle "Firewalled".