If the ally is an assassin and not losing hard, then no.
Any other class. Yes. Assassins gain Points through 1v1 kills, other classes don't. the difference inpoints are huge. Hitting an enemy once when the ally is an assassin will bring the Points gained from atleast something like 50 to about 4-7. So interfering in assassins 1v1s is a BAD thing to do.
I wait until the 1v1 is over.. I rather let my teammates die than engaging a 1v1.. I for myself prefer fighting 1v1.. if any ally engages my fight i fall back, lat him fight teh enemy.. and i let him die if he's too bad..
its hard to find Honor and and glorious 1v1-fights.. all i see is "come with me we kill this guy" "we will win 3v1" "revenge mode is op, we (3players) cant fight one player" read those quote with the voice of an idiot.
all these gangs are making me not to buy this game. i dont want to play with 3v1-******s all the time. YOU 3vs1-PLAYER RUIN THIS GAME!! for all the guys who play 1v1 YOURE GREAT keep on!
To be honest, if you complain about a 2v1, you probably shouldn't be playing this. It happens, It's part of strategy if you see 2v1 and it frightens you, run away, live to fight another day. When people group up it's leaves objectives open for the taking. Also, 2v1's aren't impossible; I've won many 2v1s maybe not as many as I have lost but I've definitely won alot. It's those 3v1s+ that all hope is lost.
McBoo addressed an aspect on the assassins and I'd like to take it a step further with elaboration.
Assassins unlock feats faster, earn more renown, and effectively become a more efficient teammate by winning 1v1 fights and consecutive kill-streaks (I believe that's within 1 life and not just in rapid succession).
Heavy unlocks feats, earns more renown, and effectively becomes a more effecient teammate by boosting and defending control zones but also by assisting/aiding a teammate in a fight.
Vanguards are a bit of an oddball in that they unlock feats, earn more renown, become a more efficient teammate by killing npc-soldiers, capturing control zones, and getting kills while outnumbered.
Players with this "I'm going to roam the battlefield and slay all the enemies in my path" mentality are shooting themselves and teammates in the foot for the long run.
For example. You come across a friendly orochi fighting an enemy raider outside of the zones. Your orochi has more remaining health than the raider but "idc, I'm gonna kill that raider because I still think this is team death match" so you attack the now outnumbered raider. It's easier to block a second opponent because you don't need to know which stance he is attacking from (unknown) the raider need only know your relative direction to his character's facing direction (pretty obvious). So, you attack, and the raider sees it coming and blocks it.
-NOW- already you've ruined your orochi's 1v1 bonus, but let's follow this worst case scenario even further.-
Raider blocks your attack and let's say it's enough for his revenge meter to fill. Friendly orochi looks to follow up on your distraction and lunges in for the kill but gets denied because raider pops revenge. Orochi is now prone and the raider obliterates his remaining health with an unblockable attack.
-NOW. Raider just got a bonus to being outnumbered and killing an opponent and you're facing an uninterruptible opponent with unlimited stamina putting you at a big disadvantage-
Raider then proceeds to make good use of his revenge mode and murder you in the face quickly.
-NOW the raider has scored 2 kills with boosted points for being a good vanguard and has the immediate knowledge that 2 of his enemies are stuck respawning which means chances are very good for him that he can either capture a zone (gets a bonus for that) or clear the front of enemy soldiers (gets a bonus for that too) not to mention he'll likely unlock 1-3 feats all from this entire exchange.
Now, if you wanted to play for fun that's all well and good but I'm assuming we all to some extent play to win. So we can now look at you. Were you an assassin? If so, you made a bad call to get engaged. Time would have been better spent hunting another opponent, making sure no enemy aided the raider, capturing a zone, or clearing soldiers.
Were you a vanguard? If so, you made a bad call. Time would have been better spent boosting a zone, clearing soldiers, etc.
Were you a heavy? If so... it's more of a grey area. You at least get boosted points for aiding (assuming you win the confrontation) but you should be aware you just cheated your assassin out of hard earned points when your character could have been demolishing the front or getting boosted points for guarding/boosting/possibly defending a control zone.
Knowledge is power, brothers and sisters. Play your role effectively, pick your battles, be aware of your environment.