Flash steps alone shouldn't make or break a character lol.

-Stark has double flash step and I as a player have never needed more than 1 or 2 for dodging or "speed running" (so using a single flash step character VS a double sure I can see, but Stark has double so your argument about one Vs double doesn't work.... because he has double)

-Being able to rip through enemies faster also helps with speed running lol, so I don't see your point.

-She moves quicker yea but that doesn't mean she will kill stuff quicker in speed running. Stark will kill quicker but can only double flash step, which in your statement double is good for speed running so Stark is still fine xD.

-The reason why Nnoitora as you said is used for both Red and Blue isn't just because of his flash steps, He easily has one of the best or the best NAD string because of his speed and the cleave he has.

I mean killing rooms quicker with a longer sprint time VS killing stuff slower with a quick sprint time kinda seems like they would equal each other out. (with Stark Vs Yoru)

-But with Ken Vs Nnoi it's a world of a difference Nnoi is faster in every aspect, Strongs/NAD/Sprint and has a NAD trait so more damage from the get go. That's why the difference is so noticeable the only plus thing for Ken is his poise.