I have at least 8 squares I use in the shop. They are:
6" try square (old metal Stanley)
8" try square (old metal Stanley)
16" (est.) Craftsman Try square
3" machinist square (for machine setup)
6" combination square (Swanson Loews(?)
12" combination square (older Starrett)
Of all the combination squares I have used, the Starrett, and a Union, one I had are by far a lot nicer than the others. Both have a hardened rule. They slide a lot smoother than the others.
The 6" combo. square is a handy size to measure set backs etc. 12" can do the same, but the smaller size is easier to handle for jobs it can do. I just found a smaller size one with a 8"(?) rule. It has the smaller head, and rule. Not sure if I will use it much.
I read, that something about the newer Starrett combo squares, being not as good as the older ones.
If I didn't buy tools at estate and yard sales, I wouldn't have the Starrett! Or most of the others!
As far as keeping the Starrett as a standard, and not using it, for actual work. Why have it? I never used a square to check another. Just use the flip it over, method.