Agreed. If the dog is powered correctly both front and back it will not only be able to work better, but also stand a better chance of going through life without the muscle and tendon injuries so often seen in dogs without the correct proportions and balance. Obviously it goes to say that the dog should be fit for purpose: running an unfit dog, no matter how well made it is, will result in injury.
have you got a pic of a lurcher that you consider does not have the correct proportions and balance,im trying to explain all this to a third party which is difficult thanks