It may be advantagious to standardize, but can also be risky. I had standardized on Agfa APX100 for all sizes but they stopped producing it in sheet film. Now, I'm leaning to Efke 100 & HP5, though trying some J&C 400 in 120 roll. My standard developer is Diafine, with some occasional experimentation. It works well with all the films I've tried, except maybe Tmax.