ModelBuilder is a waste of time frankly for what you want to do, since this type of general model requires real programming and not the pseudo-coding ModelBuilder offers. Converting the process to Python is the best advice and you will get much more help on the Forum. The learning curve may seem steep, but you won't get it done in ModelBuilder faster, since once you get to complexities like this ModelBuilder starts showing its many limitations and Python becomes much simpler to set up.
Export the 4 separate working models into 4 seperate Python files using the modelBuilder export functions as a starting point.
I don't see how to connect your description of what you are doing to the model you have posted, since you are assuming I will understand field names and other information that only you currently know exist. For example, what in the shapefile will have an average of >90? A field? A count of records? The whole process can probably be restructured to be better organized to enhance the code's ability to handle the full range of your inputs once all of the essential components in play are actually laid out in an intelligible order to people like Dan and myself.