If you need 2 kitchens to cook all the PH's, then you've probably got way too big farm plots. Watch your food stores - if you start getting scores and scores of extra food, reduce the size or your plots, and/or let the harvest rot a bit. Since you've got several growers, try turning on "only growers harvest" (under <o>rders), which means the dwarfs near your kitchens/farms will do the work there, and the dwarfs busy across the map won't hike over to pull some turnips for a few minutes.
re edit -
Let's look at the alternatives.
1) You have many people doing many jobs. They get the jobs done, and if they're lucky all end up gaining 1 skill level in each labour - maybe from No skill to Novice, maybe from Novice to (Unlabeled), whatever - but that doesn't change very much.
2) You have one or two dwarfs dedicated to each job. They do the same thing all day, all season long. They gain massive experience in that one labour, and soon are on their way toward Legendary. As the fortress grows, they're tasks are speeding up, and/or they're producing significantly higher quality products, which are keeping your dwarves happier.
Also, if you have a limited number of people in the kitchens, or making booze, you know right away if 1 or 2 are enough, and if not you can add 1 more dwarf, which could be 100% or 50% or 33% more labor and see if that solves the problem. You start to get a feel for exactly what's going on, instead of "stuff".
For the rest, essentially yes, but there should be more jobs than just "hauling". If you have ores, then you should have a metal industry. Forging an item is MUCH faster than smelting the ores (esp the multiple smelting needed for steel), so a several dedicated smelters ("Furnace Operators") per working forge. (I have 3-4/, one extra for melting down rejects and reclaims from sieges, and other metals I find like galena or... that nickel ore).
Since those furnace operators are becoming specialized labour, you don't want them wasting their time hauling - so you've trained some peasants in your pump gym or mines to a high Strong and Agile attribute, and they haul stone, and
only stone. No running off to help with food - they're the heavy lifters, and orbit exclusively around the stone industry.
Some go into your military fitness and training program. Some go into support industries like the butcher/tanner/leather/bone/bowyer cycle, or the weave/dye/clothier cycle - if you're not excited about those, then 1 dwarf could cover many parts, since they won't be doing any one full time. But, for what they do, they'll be the go-to guy when it happens.
One or two woodcutters/plantgatherers, who do all of the outdoor stuff and never put down their axes. Get one or more apprentice masons who help with construction but are not allowed to make anything but blocks until they're high skill.
In short, branch out, allocate specialized dwarfpower to your different areas as needed. A fortress could run if you turned every labour on for every dwarf - but it runs better with just a little organization, whatever that word means to you.
Check out this wiki page:
http://www.dwarffortresswiki.net/index.php/Industry