Panels indices/reference after grouping and joining

Hi,
I have wall panels and I grouped them by direction then I joined each group to create wall stack and I moved them to be distributed next to each other. Then I exploded them to the original panesl (faces) using deconstruct brep, but when I want to assign each panel a property (thickness value), I noticed that their indices already changed after all these manipulation.

Is there any way I can keep the indices for all panels same before and after grouping, joining and deconstructing? if not, then what is best solution for this problem?