Including the drop (~10 seconds where you can't DPS) you have ~75seconds to push Soar @ 75% which requires 14,700 DPS
Most average DPS will push out 2500 DPS including the drop and then the wind up after the drop (15 seconds for putting debuffs, dots etc before Soar)
So that leaves 4,700 DPS for the tanks and healers to take up. Tanks can typically be 1400 - 1800 depending on party comp, so we'll say 1400 for MT and 1800 for OT -> 3200 which leaves 1500 dps for the healers.
From what I've seen each healer can easily push out 1500 DPS because the tank is taking half of the damage the Fairy Pet can heal on it's own (~450 DTPS and the Fairy can heal 900/s not including Rouse)
So say both Healers know how to put their dots on and spam Malefic II/Broil this reduces the DPS requirement to 11,700. (14,700 - 3000 = 11,700)
DPS 2200 X 4 = 8800 DPS
Tanks 1500 DPS = 3000 DPS
Total = 11,800 DPS
Required Healer DPS = 2900 Combined
Which is so incredibly low that to not skip Soar either the DPS and Tanks don't have a pulse or the healers aren't contributing as much as they think.
Also don't take those Healer DPS numbers as gospel. I was doing 1700 DPS as SCH with the Sophia weapon @ like i260 so healers can probably contribute significantly more @ i270 with i270+ weapons etc.
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Single Tank Strat - Average to Skilled Players
DPS 2200 X 5 = 11,000
Tank = 1500
Total 12,500
Required Healer DPS = 2200
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Single Tank Strat with Decent Players @ i270 90%+
DPS = 2650 X 5 = 13,250
Tank = 1800
Total 15,050
Required Healer DPS = 0