PTH, the answer, as is always the case when discussing pheasant hunting, is "it depends".
As Shawk said, it depends on cover. The fields I hunt, which are primarily either grass less than 30" high, or milo stubble about 18" tall, don't produce well when dogs are running out ahead. Birds flush long wherever the dogs are working.
But, when I went out with a new hunting partner and his 12-month old dog who stayed close, the birds were not as wild as when I hunted with two buddies and their two dogs who went further ahead. So, the factor of the young dog staying close, and not crossing too far left-to-right, seemed to help immensely.
Also, when hunting with dogs or without, keep your mouth shut! This goes for everyone in the party, including dog owners. Don't be calling to your dog, or whistling to your dog, while in the field. Pheasant are not deaf! I have shown time and again that being quiet in the field is a huge help in getting close to birds, whether with dogs or without.
It irritates me to no end to see the bird-hunting shows on T.V. where the participants are cajoling each other, or calling out "Got a dog on-point here". We see birds flush long on those shows, and the hosts don't seem to correlate the long flushes with all the noise they are making.
If you are having problems with birds flushing long, take an honest look at how quiet you are in the field. If there is anything more than "Hen" or "Rooster" being said, you are making too much noise. If you use blockers, ask them how far away you are when they can hear you. Sound carries, and I can hear hunters talking over a quarter-mile away. Birds hear that too, and get out of Dodge.
Another factor in the cover I hunt is (and I know I will get flamed for this, but it is true) blaze orange on the front of your body. Birds don't see in black-and-white, so that blaze orange is easy for them to see if your cover is shorter than 3' tall.
If you feel unsafe hunting in less-than-waist-high cover without blaze orange, you need different hunting partners. The visibility of blaze was demonstrated last season and this season, many times over. I had new hunting partners come out, and some wore blaze orange. Birds always got up much further in front of them than in front of those of us with blaze on our backs, or none at all. Again, this is all cover that is under 3' tall, so we could see each other very easily.
When some that had blaze on for the first day changed to no blaze on the second day, they commented about how much closer the birds were flushing. It makes a huge difference!
Wear blaze if you are in waist-high cover, or higher, as the birds won't be able to see you from the ground. But, anything less, and you may as well have your full-choke in, as you will have long shots.
If you are hunting with one dog, or 3, silence and low-visibility are more important than the number of dogs. How you run your dogs is up to you, as some produce better by staying close, and some range out far, and push the birds back to the hunter(s). But, stealth is important no matter how your dogs work.
Good luck, and have fun hunting!