"Used to be, likely still applies, not a good idea to mix different types/brands of grease. "
I would really like to see some proof or research/testing done by a reliable source to back up that statement. Having serviced hundreds of semi trailer units and not knowing what grease was used previously, it was a rarity, rarity that a bearing in our fleet of over 10k units ever had a bearing failure. A bearing was only serviced when the unit was brought into the shop for a brake change. That could be anywhere from 1 year or 5 years. Servicing wheel bearings every year is just nonsense. I call malarky on that one.