Figure I'll weigh in on the Orb phase mechanics from a personal perspective.
During the first week of content, we arrived via experimentation at the following conclusion regarding the phase as it fits into the fight overall:
The less time you can spend on orbs overall on that phase, the more time you can spend on the boss, which (when progressing) is incredibly important.
Additionally, there is a 'breakpoint' for each raid group dependent on DPS comp etc, where killing another Orb wave becomes a DPS loss when applied to the fight overall, when compared to simply ignoring said wave and keeping all DPS on Elegon. This is really only applicable to the 2nd phase 2.
Based on the above, any AoE DPS that can be done to the orbs when they first appear (normally, since most DPS classes cant reach them all once they've started moving away), is a huge boon to the raid. It increases the raid's uptime on Elegon during this phase, since each player (tank or DPS) is able to spend less time running/focusing an orb.
I'm sure Zagam is correct to say that a warlock assigned directly to one orb of the 6 cannot simply spam seed and hope to kill his own target via that damage. He is also correct to criticize a warlock that is specifically assigned to an orb, then simply spams seed and expects his DPS partners to cover his slack without prior communication to that effect.
However, going by what Jvchequer is saying (correct me if I'm misinterpreting here), he is using a pre-arranged strat in which his class is directly assigned to maximizing AoE DPS to all orbs on that phase, for nett benefit to the raid. This is also fine, so long as it's communicated to everyone before hand and is being deliberately incorporated into the raid's strat to help down the boss faster. No doubt it's a nice boost to the lock's DPS and he gets to give all the other DPS a cheeky grin, but the reality of this encounter, imo, is that having the luxury of a warlock to do exactly this is quite a boon. We are using a similar strategy on our 10man, in which the AoE viable classes are assigned to 'float' and deal maximum AoE damage at the onset of each wave, while we have 2 dps and 1 tank assigned directly to an orb on each side (tanks inthe middle for ease of coverage). Those floater DPS then backup anyone whose orbs are still high once the orbs have moved beyond the effective range of their AoE.
Obviously, like any strat, it's just a trade-off which may or may not work depending on your raids strengths. That's half the fun of raiding, finding out how to best use your comp to tackle raid mechanics