It just shows that Mihawk & Shanks being above Roger is a Popular Idea among Japanese Readers, and Dragon is up there as well or close.
This isn't Proof of anything, but it adds more weight to what We say this Story is trying to tell us.
Personally, i've always seen those East Blue Top Tiers as Best at what They represent.
Shanks is Strongest Pirate Captain, Beckman is Strongest Pirate Subordinate,
Mihawk is Strongest Armed Fighter while Dragon is Strongest Non-Armed Fighter,
Basically Shanks/Beckman are who Luffy/Zoro must Surpass Role Wise,
While Dragon/Mihawk are who They need to Surpass Combat Skills Wise