First, there is nothing wrong with seeking an advantage in ack protection. As you stated, a player coming in with an alt advantage has done so to gain advantage so why deny a lower pry any advantage the player has available to him or her. Keep in mind too, if you are low and near a base you often, not only low, you are slow. Players like rocky look for these exact situations, low and slow.
So many times have I heard on vox some say look at that guy running to his ack when there were four of five green guys to one red guy.
Please do not beat up players that play the hand they are dealt.
Now back to the real meat of your post. I use to fear those pesky P-51s, 109s and 190s. Not anymore. 9 out of 10 of those have poor throttle control since alt advantage is the only part of the game they know. If they turn hard, they go slow so If I don't kill them another player will.