Note: I'd appreciate getting an answer that's not "Get a life... stop playing wow, &c."

I have a few characters with the following professions:

Skinning & Tailoring
Herbalism & Alchemy
Mining & Engineering

I just created a rogue and think that Skinning and Leather-working would do well, but i'd rather do inscription and herbalism.

My question is this: Is it worth doing herbalism twice* on two different characters, surely it would be easier to use my main herbalist to farm materials more easily with a mount and everything - and just send them to the rogue. So what do you think I should do?