Most of the above is right advice in some respect or another.
Tuff part is the situation you have, is like all golf courses. No two of them are the same. Hence why every community course is NOT like Augusta National.
When I was part of the crew that built the course that inspired the Senior Tour, I tried hard to learn from the Head Greens-keeper all I could. Tampa Palms went from molded dirt to tournament ready in less than 4 months. Mr. Hills the designer and Mr. Palmer came out to see the status at end of third month and caught my boss playing with the fly-mower. Flinging it like a Frisbee across a very undulating green was impressive to us, just not for those gentlemen. We were bored, what did you expect from a gang of hungover stoners fresh out of high school having to work a Saturday morning after payday. Lot of fun and hard work. Can't tell you how I hated having to fix washouts and re-sprig them suckers. Was my particular gift of being able to cut cup holes and repair the old that saved me from several of my youthful indiscretions.
Growing grass is a little different from what am learning about real farming, with a lot of crossover. Basically smooth grass starts at the foundation (Dirt, dude, Its all about the dirt, boss used to say). They can grow grass on concrete, its how well aerated the dirt is underneath, along with nutrients, that determines how the grass will grow. Hence why golf courses spend oodles of $$ having the fairways and greens plugged. Mix in some nitro w/ a few other goodies into white beach sand and drag harrow it in. Gives the roots a direction to go, along with much needed oxygen for the nodules. Grass will thatch itself almost to death, depending on type grass and your location. Aeration of soil on established grass helps smooth out minor imperfections.
Biggest problem is what is the slope? How is draining? If water puddles up too much after it rains, will drown the roots and stunt growth. Keep a flow going someplace that is more naturally planted that can handle it. Xeriscaping is an art. All parts must work together to keep the lawn extra healthy.
If its only a little off here and there, you need to trick it into raising up in low spots by topdressing it with light sand/dirt combo. Mix a little crushed fine charcoal(not the self lighting kind, go plain generic, it works great) to a sandy gray look to get rapid blade and root expansion. Takes a few weeks to get low spots out, but lets the grass do it for you. Take a shovel full and spin it kind of like baseball swing over general area. Lightly pack it by tamping feet to make top dressing stick. Then very lightly water so as not have the sand mix run off. Low spots will rise easily over time. And a good lawn takes time.
Higher spots can be simply hard raked. Use the tines to loosen dirt. Then flip rake and pull dirt out. Gently work the high spots down. Little at a time. If you wait between every other week mowing to do, will work down easily. Concept here is as the dirt is moved out, the mowing action will encourage the grass down, and with it the dirt level as you remove it. Building it down as you go, so to speak.
Rolling it over with a roller filled with spikes will help it aerate and grow more consistently. Watch the patchiness for areas that are low in nutrients. Mix a little scotts grass feed with above sand mix to help.
If you do go to the extreme of plowing under, then blade it to general shape you want. WATER ROLLER pack it down with half filled roller. Plant your seed ONLY AFTER you have the exact shape you want. Anything else is wasting time and energy. Grass will grow on concrete, so you can grow it on rolled dirt. Don't pack it too tight before seeding. Then just use a push type fertilizer spreader loaded with light sand to top it. Otherwise the seed will just stick to the water roller. Had to redo 2 holes because under pack was too loose and washed out. 125 gallon water roller pushed by hand ain't no fun in the Florida summer heat, let me tell ya. This light sanding is similar to top dressing it, just with seed. Then afterwards do you want to full press it to pack top layers and prevent wash outs. If you have tiered levels or mounds you want to add in, try using plastic edging material running in rings around the mounds. Looks like a topographical map if done right, and prevents rain and watering erosion before grass sets.
Running discs back and forth, whatever pattern you use, will help the aeration principle. It just may not smooth it. Discing it well to loosen it, following with a box blade to shift it around is better. But once gets there, is where the rollers come in handy. Depending on the type grass, chain/drag harrows perform similar function to "spriging". Most lawn type grasses will repopulate itself through sub-roots. Bahia is the most common seen sprayed on sides of roads. Kind of looks like hay shot over area. When spriging grass, run a set of discs in most non aggressive position you can, and just barely pierce the dirt about 2 inches at max. It will help the grass pieces into the slices made by the discs and give a more solid rooting with quicker growth. And hopefully rain only lightly will allow it to set and grow like wildfire.
Getting into St. Augustine's, Bermuda's, other hybrids, and some of the new stuff gets into a field I haven't been in for years. There are ton of choices in grass technology nowadays that was just beginning when I worked on my two golf courses in much younger days. Am sure you can find the type you would like, its out there now.
Hope this helps a bit to point you in direction that works for you. There is a whole internet full out there and this is just some of my limited experience.
The land we are working sounds similar, previous timberland that was harvested and needs smoothed after logging and piling.
