Best practice to secure data (row level) across multiple models

[Yunus]

I have to secure multiple fields at the row level in FM.  I can not do this in one model because different hierarchies of data are in use and users can be members of multiple hierarchies and a single model with security applied would be too restrictive.

My solution initially was 3 models, identical in all ways except security applied and package names.  This requires a lot of maintenance because a single change to a model requires 3 updates and increases the chance of mistakes being made in one of the models.  Then I read about linking and segmenting and thought this might be a solution.  But security is transferring back to the main unsecured model from the secured segmented models.

I need some advice on the best way to accomplish this.  I like the idea of segmenting but I only want updates to process from the parent model down to the child model, not the other way around.  Is that possible?