4 is too small. 5 is still too small.

We need 6 man parties. 1 tank, 1 healer, 1 support/dps, 3 dps.

And raids that actually use 9 to 12 of those parties, not just three of the "full parties" that we have now. No, Coil is not a raid - its just a "full group" as opposed to a "light group".