You're correct to be concerned about the difference in level between
inside and outside.
You don't say what "the drainage problem" was.
Certainly, as Rick says, it's a good idea to leave the working space
below the floor.
As Bob notes, the problem is to keep water out of the space.
As long as you think you can keep the crawl space dry, you are o.k.
In addition to directing roof run off well away from the house, sloping
the yard surface away from the house, sodding for improved run off, and
making sure of the water table height, you might consider directing
some conditioned air into the crawl space. This can be done with
passive registers or a fan.
In the South East, outside air is often too humid to be useful in
lowering the relative humidity in crawl spaces.
TB