Your set up should work just fine. The plan of plow, disc, rototill is the first class way to do the job. The guy must be a good friend since the work will take extra time...especially if you have to haul it all to the job and back.
If it is virgin ground then the plow is likely a good idea for the initial break-up. Discs sometimes require several passes if the area used to be permanent pasture or the like.
A tiller on new ground can leap around a bit and shake the heck out of the tractor. Once the ground is disturbed the tiller can zip through fairly quickly...but two acres will still take a while.
You will have to make the call on what tasks are necessary depending on the ground conditions.
BTW, you aren't nuts, just willing to do the best job possible.
Not sure what your co-worker said but the little tractor and your determination will show what a fine job can be done.