I have drawn a similar conclusion but do still advocate their benefits, I do use ASB's but not in excess or with every shave. When using an ASB or other post shave treatments my head is telling me to use "a little bit more"than I know I need, rather than what is needed. We do the same when making lather so it is something we are conditioned to so automatically; I am sure the manufacturers are happy that everyone tends to use/buy a "little bit extra, just in case" whether it be food, paint or shaving products. I find this "little bit extra" on application of ASB's, apart from being wasteful, can leave my skin with a greasy layer sometimes this layer can have the adverse effect of giving me collar chaffing because the skin it is not dry.
One of the most recent revelations I have found is the use of a little shave talc, I find the absorbing effect of the talc reduces any collar chafing and also calms my skin and reduces any redness very quickly.
Some days I do exactly the same an Andy, shave then alum followed by an AS splash, some of the scents in the splashes are quite short lived, I find Proraso to disappear quickly so I leave it a half hour then add some shaving talc and a squirt of cologne (not on the face) and that's me done. Other times when I am not going out I like to use a nice balm after shaving and just leave it for an hour or two. Later in the afternoon I will go slunge my face with only warm water and then use an aftershave like AV or Proraso with some with hazel thrown in and this conditions my skin nicely for the next days shave. The oils in my skin, or what has been absorbed from the ASB, surface over the rest of the day and my skin is ready for the next shave.
Overall my findings are that I have a lot of products and I only use them as and when required or desired, some days I skip ASB and some days I don't but it is interesting that it has helped you. I might try it for a consistent period and see if it suits me.