Tried some PvP for the first time.

I got up to a spot in Anor Londo I didn't want to deal with ATM so I decided to try some PvP for the first time. I went into that forest area you unlock with that 20 000 soul key and joined the covenant in there.

Though I'm new, I still understand the unwritten rules set by the community (let him clear the area, heal up, bow, etc.). As I'm only SL54(i think) I didn't expect to win any invasions at all. The thing is usually when I invade there'll another phantom or two in the area as well. I never interrupt other people's duels but almost always when I'm dueling, another phantom will go in and try to backstab him or something (when it happens I back off and let them fight).

Basically I'm just wondering if It's generally frowned upon for phantoms to 2v1/3v1 the forest invader and even if it's possible I'm being too nice to these people (even if I am I probably won't change how I play).