Number 1 and 2 are chisel plows. The only difference between them is the sweeps and spikes. Number 3 is a field cultivator, or here and in MN sometimes called a "digger". A chisel plow will have 500-1200lb trip shanks while a field cultivator will have 120-200lb trip shanks. Back in the days of summer fallow (not that long ago for us actually), we ran 16" sweeps on the chisel plow because they would kill weeds, but also throw ridges that were a lot less likely to blow. A field cultivator would leave the field way too fine and smooth.