When I learnt that the 722.118 was provided in a form of "vacuum only" and "no vacuum but with a solid rod connection to the throttle" I lost all hope in trying to understand Mercedes transmission numbering policy.
As far as I can make out almost anything goes - almost anything can happen. It isn't like they are shy with making up new numbers for things. In the case of the above they could at least have given us a 722.118A and a 722.118B (same thing happened with the 722.117 too). It really doesn't help us fixer upers...