The gear ratios are similar but the shift points are different.
The torque converter and flywheel for the 2.6 and different to the 3.0's
The 722.3 was designed for a much a higher torque load than the 722.4 and as such is a much heavier unit.
The 722.3 must be squeezed into the 190e.
Also necessitates a change to the end of the transmission where the flex disc connects the trannny to the drive shaft.
The different coloured vacuum modules represent different shift points for different engines.
The 722.4 transmission variations were shared by the 4 cylinder engines, some diesels M103 2.6's and M104 2.8's.
The 722.3 were shared by larger capacity M103's and M104's as well as V8's.

There has been much discussion over the years wondering whether or not a 722.3 would actually fit into a W201. Now we know of at least one. Be interesting to know whether or not the transmission tunnel needed to be modified to fit it in.