a green ^^ is a group mob.. solo it at your own risk. My predator at 19th can take on green double ^^ and win.. takes decent poison, good weapons and gear and I have my agility cranked to 76 and wanting it higher, but yes it can be a TOUGH fight.... I have a LOT of Adept 1's as well, pierce, impale, shadow blade, back shot are my biggies at adept 1.
it also takes good use of abilities and HO's.. stunning strikes and keep the mob stunned and off balance.. lower it's attack opportunities.. but it's very easy for something to go wrong in a fight with a double ^^ green.. which will often lead to death.
that said....
my conjuror can walk all over double ^^ green mobs as though they were a welcome mat... Orange con solo's or less are merely XP on the hoof to her... only an orange solo or higher even has a chance to beat her.. every thing else is guaranteed to die unless I'm sleep at the keyboard. Only thing she has issues with are group mobs that come in large numbers... 3 or more to be exact.
my enchanter at 15th level scoffs at certain groups.. a group of 3 greens with no ^ are beatable, but it takes strategy and careful spell use.. a group of 2 greens with no ^ indicators are a cake walk.. as is a double ^^ green that is "alone" they simply cannot beat her... Orange con's are somewhat tough right now due to needing to up a few of her spells to adept... yellow and down however should simply die when she looks at them.. the XP is just that easy to get for her.
in short, as it should be... mages and priest can and often will out-solo a melee.. priest have the ability to self heal giving them enormous staying power.. mages have the ability to stop the mob in it's tracks at a risk free distance and blow it to hell and back.. (especially Enchanter...), Conjuror and Necro's simply throw the summoned pet at the mob and relax and enjoy the show in near absolute safety..
to put it in perspective, I have soloed Orange con solo and double ^^ green with my conjuror and not taken a single point of damage and done so multiple times, with my conjuror I consider a fight tough if I get hit at all.... good luck finding any melee class that can make that claim.