1. Never happen, so what's the point?
2. Who said that Byakuya is smarter than Tsukishima, smart wasn't really any equivalent, Tsukishima has know about everything Byakuya has knew, he even teached him his techniqes, he literally know any technique or tactic Byakuya ever made, that was just arrogan from Tsukishima's side.
3. Saying that you are stronger than someone is not arrogant. Tsukishima's words were nearly true, arrogant is what Yama did agaisnt RoydYhwach, not what he did against Aizen. Yama never lost to Aizen. It was also imlied that Aizen would be dead by Ennetsu Jigoku, after WW explode, Yama who tried to stop explosion (explosion that would kill Aizen), was left nearly dead, but still was able to cast 90s level of kido, and damage Aizen, which further my point here.
4. Byakuya did outpaced twice. If we take that first time he was just surpised, than why didn't he counter it second time. Ichigo was faster than Byakuya, than he just slowing down, what made them equal in speed, he started slowing down because he take a hit from Senbonzakura, when he was still in shikai, which later take effect, that was proven with their conversation:
Byakuya: "I didn't get faster"
Ichigo: "You want to say that I got slower".
5. Byakuya was faster than Zommari, it was proven when latter used Utsetsumi and outpaced him.
6. Never said that Starrk used Sonido. One can use just his raw speed and still be faster than him using sonido. Ichigo's raw speed is faster than his shunpo speed. Zaraki don't even know shunpo, he also use just raw speed.
7. Manga didn't stated that he used sonido. So, burden of proof is on you, not me, you need to give proof or at least good explanation why did Starrk used sonido.
8. Where was stated that no one believe that Zommari's sonido is not fastest? Fact and feats say that his sonido is best, tho, just raw speed of others are greater than his.