I'll say BS to your face. A low P-40B agains a higher La7 is a one sided fight. And again, what point to continuing a fight you can't and won't win, when you can get away, and come back on more even terms?
It all depends on the pilot. Yes, the La 7 would have the advantage due the altitude and energy but that doesn't translate to a one sided fight.
Last night I was bounced by a higher P-51D with a very large energy advantage. Each time he would make his BnZ pass, I would break into a Low Yo-Yo into his attack. As he went back up on his zoom climb, I would level out and wait until he made his pass again and again, I would turn into his attack using a Low Yo-Yo. After the 3rd or 4th pass, instead of zooming back up, the Mustang went into a High Yo-Yo, thinking that I would level out again after I made my breaking turn and he'd be able to saddle up on his six. What he didn't realize is that with each Low Yo-Yo I was doing into his attack, I was gaining a little bit of energy each time. So when he made the mistake of going into a High Yo-Yo after his last pass, I had sufficient energy to continue my turn into his attack and follow him up as he did the Yo-Yo and was able to close on him and removed his wing for the kill.
Sometimes the best defensive tactic you can do is go on the offensive and sieze the advantage from the attacker.
ack-ack