based off of what has been shown team zaheer takes team aang in round one in a landslide these gues have taken out the white lotus like they where a pack of amatures pli has combustion power something no individual member of team avatar has shown copasity to take on alone sokka needed a distraction to from zuko and toph kind of got lucky so in one v one zuko has no, chance she takes him out and moves on to help the others. zaheer was apparently hell to deal with as a non bender now he has airbending I don't see aang handling a fighter of that caliber with just his airbending I give toph vs ghazan hes shown nothing but the magma trick that toph cant handle. ming hua takes katara down with her her high flying attack style she was able to beat eska and her brother and they were able to fight korra the avatar. kataras tough but in her younger years without bloodbending shes been somewhat hit and miss with her water bender vs water bender fights. with that it comes down to pli ming hua and zaheer vs toph and she is good but not that good. even if katara can beat minghua then she stuck fighting zaheer who beat kya like she stole something.
round two aang may be able to beat zaheer now with all his elements evening up the numbers so I give this to team avatar in a close battle.
Just because they were White Lotus doesn't mean they were high level grandmasters like Iroh, Bumi and Pakku(there are ranks). The ones they fought were more or less canon fodder and does not compare to the grandmasters that appeared in the original series.
Zaheer has shown alot of skill, but he hasn't had his Airbending for long. He's an impressive bender already, but I don't think he's quite on Aang's level yet.