Rod, If you tag/mark 5 fish so you can identify any 1 of the 5 fish, you can absolutely gain knowledge from that.
Over a years time, what you had last year and what you have this year can tell you many things-especially about growth rates (read proper forage). Not all 5 will achieve the same growth rate/size. If 4 grow substantially then you know things are good. If 3-4 don't grow, again, it's a look-ahead view at what your management plans need to be, but it's "at that time", it's always changing but the info that can be potentially gained is why, I believe, most of us are here.
It doesn't matter how a tag/identifier is made, it's what we do with the data we get from it.
