Personally I was thinking this would be better served by just giving us tier I of Double attack job trait than a spell.
Actually, I'm venomously against this. I'd rather hope that the Double Attack rate from this spell is higher than the natural job trait from Warrior, as we're having to expend MP and cast time to use it.

If we want a Double Attack Trait, we can sub Warrior for it, then STACK it with this spell.

It is just a shame that BLM is the only one that can handle situations like these where a tiered ga form of silence and paralyze would be just as useful.
Um... Bard, BLU, SCH or Rdm/sch can all handle links in an AoE to various degrees. WHM and DRK can also add their additional single target sleeps to the mix if they wish. We're not as hurting for more AoE sleeps as you think.

AoE Paralyzes and Silences, I can see getting more of, though, just having Accention AoE target white magic Enfeebles would work too.

I say this mainly because I severely doubt SE will give RDM much more in terms of AoEs. They've always viewed RDM as more as a single-target sort of character.