Well, in JG 54 there was a pilot who said
"If you got home from a mission with a kill, but missing your wingman, your mission was a failure".
Hard to help your wingie when ya got one enemy on yer six, but ya gotta try

.
There are times when one arrives at the scene of a fight only to see a friendly engaged much lower with plenty of cons higher than him, and if you help him you know that you'll both be at a disadvantage. If you don't, he dies.
What to do? IN IN IN!

Use the extra speed to at least drag the high enemies down and towards more friendly territory.
Also in MA, when those hi inb cons come in, they usually do not operate in pairs, in which case a rotte has a good chance of suckering them in and getting shots at them.
Rottes or schwarms are much harder to deal with from a disadvantage.
All depends on the circumstances.
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Baron Claus "StSanta" Von Ribbentroppen
9./JG 54 "Grünherz"
"You filthy piece of distended rectum! DIE allierte schweinhund!"