I've got a solid SK/ENC/CLR from my original group, other 3 were DRU/ROG/PAL up to a point that group did well, 3 way heals and rez, making survivability quite high and most wipes were avoided, all well geared for EOK era, and moved to showbound when we hit 110, then upgraded bits as we could however we hit a wall when we got to t2 ToV and beyond as they just couldnt bring enough dps, could pump out a ton with the druid but he was dry and panting 3/4 of the way thru a fight and rouge cant hit squat given a 2k dex when the content is tuned for much higher. so i swapped out for 3 mages, one that was already 106 and leveled up fast, the other 2 pled up from 65 and 85 over the course of a couple weeks, now they are 115, 114 and 113 and already challenging the SK for top dps now and then on normal fights. as far as gear goes only one of the mages is well geared, other 2 are in snowsquall and a couple other drops, but non visible is still mostly garbage.
first iteration struggled at the mermaids in CS, second iteration whomped for hours with only a couple bad pulls that caused wipes and as i said so far only one is 115 and havent spent much time on aa/gear yet, and they replaced characters with years of development/gear.
i set up an audio trigger trying to tune the mages casting to get the best use of alliance, with 2 in the group it goes off every other fight or so, assuming the critters being killed can live long enough to get hit enough to trigger, with all 3 fairly consistently about 30 seconds in there is a big 3 mil point burst from alliance, longer fights with just the one 115 mage casting it it can go off 2-3 times if the fight drags on. keep in mind each fulmination strike is roughly the same damage as a 115 wiz mana burn, this will only improve when the other 2 reach 115 and will be casting as well.
other benefit is when SK goes down, before it was a toss up as to how quick the paladin would jump in and actually tank instead of try and play cleric letting the thing rampage thru the group, requiring more heals. now SK can rez pause a second pop unity and be at least half buffed, meanwhile the pets are having fun playing taunt tag back and forth with the well occupied critter.
admittedly there are ton of benefits to using a melee dps group, but the gear including type 5 and 7 augs are critical. mage group can be up in minimal time with shit gear and still have mindmelting dps in a burn