1 acre size. i would say a tiller.
a plow, disc, drag harrow, etc... generally requires you to be able to pull straight in one direction and once on other side being able to lift the implement out of the ground to make any sort of turns. granted same thing with a tiller. but tillers you are more likely be able to back right up to different areas (house, sheds, driveway, etc...) and drop it down and go. unlike plow, disc, drag harrows, they need a few feet or more, before they actually dig in and start doing there thing. were as a tiller, you can set it down running, and let it slowly work its way down to depth, before you start moving.
the hard compact clay here. a disc would only chicken scratch the surface. and i need a plow to get down further to break up the hard pan and help tear the roots apart on the grass. once the couple inches of roots and hard pan torn up. then the disc would fall down into the dirt and begin tilling/chewing up the dirt and breaking up clods.
i overly abused the old allis chalmers CA with 2 bottom plow and disc. more so the disc. and ran as fast as i could MPH wise and just dropped the disc and let the dirt fly. and disc'ed a few areas 6 to 12 times. making different paths and at different angles. to cause the ruts, erosion, bumps, etc... to be spread out over larger area for smoother yard. but issue is there were still some "low spots" not as deep and not bumpy, but areas were water would collect.
if i had a box blade at the time, i would have..
1 plowed to break up sod into chunks and get deeper to break up hard pan at the surface.
2 disc-ed a few times in different directions to break up what i could (would of smoothed it all out)
3 ran a box blade to help fill in low areas and take out some higher areas
4 ran disc again to smooth out the little ruts and small little high spots from simply driving tractor over the area and dealing with some up and downs of box blade
5 ran drag harrow a couple times through it all to drag out any odd clumps and get a finishing touch.
6 seeded with grass
7 disc or drag harrow to work the seed in the dirt a little bit.
8 toss some straw out on hills / erosion areas.
if i had a large / wide enough tiller...
1 tilled
2 box blade to smooth stuff out here and there.
3 maybe tilled again pending on how much rutting i did (from tire tracks)
4 drag harrow
5 seeded with grass
6 disc or drag harrow to work the seed in the dirt a little bit.
7 toss some straw out on hills / erosion areas.
FEL (front end loader) can back drag and move dirt around, but just to rough and takes good amount of experence to get things level, compared to a box blade
a 3pt hitch rear blade, does not really allow you to move dirt were you need it, and requires fine control of 3pt hitch linakges to get it working for smoothing stuff out in large areas.
Harley rake could be an exception, to above... but it would be the "final touch up" just before tossing seed out. wanting to get down deeper and bust up the hard pan and get roughly the same compaction of soil across the entire yard would be what i would want to keep the bumps / ruts / low spots / frost heave of ground a way for a longer time. dealt with to many ruts in yard from driving tractors through wet soft yard.
sacrifice teeth on say a box blade, might work if you made multiple passes in different directions, to work the area over. vs using a tiller or plow. for me a disc just won't sink into the dirt.
to re-hit on compaction of soil.... just like filling in trenches. you toss in a couple inches at a time and compact the dirt, then anther couple inches of dirt, and then compact. i would want the entire yard to have the same approximate compaction clear through the yard. a few inches deep.