Admittedly this might be the opposite of what's intended, but as an AG and BH player having the usage stats for, say, Arceus reflect the usage of multiple per team is in fact extremely useful. Furthermore, if the point of tiers is to make a threatlist, then the difference between 40% of BH teams running imp Chansey and 20% running 2 is largely academic, and still gives the same teambuilding info.