Putting a sword in your OH as sub is a DPS loss because it will proc fewer poisons (see poison application rate; flat % chance per hit). If this is acceptable to you, and does not push you under the minimum damage the people you play with expect for having a good time, it's acceptable.
It's not the best option, but "acceptable" is a somewhat nebulous term, and you have to decide for yourself how much the loss of poison damage (shouldn't be HUGE as sub, but I'm not sure about damage breakdowns in PvP) matters to you.