WOW...that is an extensive list. Gotta go soon so I'm only looking at the top tiers, but I feel like a second, or maybe even third tier is needed. There's a potentially huge gap within the SS tier (Roger/Whitebeard vs. Shiki/John) and S tier (the admirals vs. current yonkou execs). These are all the people that are going to come up soon in the series.
Agreed, what I may do instead of alphabetically organizing them is rank them in each tier which would help determine if more tiers are needed. Gave some respect to the members of the Rocks pirates lol.